“Get a Personal Trainer for Your Computer!”©

NOTE:  Items highlighted in RED are defined elsewhere in this Glossary, while items highlighted in BLUE are site links for further information.


C++: This is a very popular programming language C++ logoreleased in 1985.  It is “object oriented”, meaning that one if its primary benefits is the ability to reuse and modify the code without extensive rewriting, as was required with many previous programming languages.  It also has the advantage that it can be “optimized” to run extremely fast compared to other codes.  It was based on the original “C”  programming language created by Dennis Ritchie in the late 1960s at Bell Labs (which of course was based on the “B” programming language before it).

CA:  Certificate Authority. An authority that issues (also revokes) a SSL or code signing certificate.  See also, PKI.

CABLE:  Cable is the plastic sheathing which contains the wires which are are run inside it.  There may be different numbers or gauges of wires or they may may be twisted or even have additional layers surrounding them, depending on their purpose.  (1) Cable can refer generally to internet connectivity over cable television coaxial cables.  Click HERE to learn more.  (2) Also, the term can generically refer to network cable, including COAX, ETHERNET and 10 BASE T (BNC).  Each type of cable varies according to speed, shielding, security and connectivity, but all are  almost always faster and more reliable than wireless networking.  Click HERE to see photos of  various types of cable and their connectors.    See also Structured Cabling, How To Make Your Own Cables.  One more note:  Cables can go bad! Don’t dismiss a bad cable if your devices don’t work or don’t work well.

cable vs wire

CABLE SELECT:  A feature of many PCs that allow attached hard drives to be identified according to the order in which they are attached to the cable.  Otherwise, the jumpers on each drive must be manually set to either Master or Slave designations, depending on their use.  (See the letters “M”, “S” or “CS” on the drive case.) Click HERE for photo of jumpers on a hard drive.

C & C: Stands or “Command and Control,” a type of server which takes over operation of a group of computers (sometimes “botnets” for nefarious purposes), often via an IRC server or a specific channel on a public IRC network.

CACHE:  (1) Derived from the French word for “hiding place,” cache is short term storage designed to speed up certain computer operations by temporarily storing data in a location where it can be accessed quickly. It is distinguishable from RAM and buffering by the location and purpose of the temporary storage.  Cache is specialized memory used by the computer’s CPU to speed up access to the RAM; it acts as a buffer, looking ahead and trying to anticipate the next item needed from RAM.  Cache is often designated Level 1 (8 - 128Kb), Level 2 (above 128Kb) or Level 3 (>128Kb), each of which divides the allocation between instructions and data.   Level 1 and 2 are usually embedded right on the processor chip itself, while Level 3 is generally on a separate motherboard chip, which is slower, but less costly and can store more memory. See also branch cache(2) In Internet jargon, a “cached” page is a archived (stored) “copy” of a web page which was once viewed through an Internet browser.  It is stored on the hard drive of a computer making it easier to load on subsequent viewings.  It may not be the current version of that page, and the page may no longer even be available, but it shows what that page looked like at some point.  See, for example, the content on WaybackMachine.  For other types of memory, both temporary and permanent, see MEMORY.  And for the difference between archive and backup storage, click HERE.

CAD and CAD/CAM:  Computer Aided Design. A general term referring to those programs that are used to create designs (architectural, manufacturing, etc.) using computers.  One of the most popular CAD programs is AutoCAD. In integrated CAD/CAM, products designed in CAD are input directly into the CAM (Computer Aided Manufacturing) system.  See also EDA, for the merger of CAD and CAE (below).

CAE:  Computer Aided Engineering. A broad term used by the electronic design automation (“EDA”) industry for the use of computers to analyze and manufacture products and processes often created by CAD (above).  The term includes CAD to use the computer for drafting and modeling designs, and CAM for managing the manufacturing processes. See also EDA, for the merger of CAD and CAE.

CALL:  A requestHardware or software requests permission from a computer’s operating system to run. A system call is how a program or API requests a service from the computer’s operating system kernel.  It could be to access hardware (like a DVD drive) or for software to access to an operating system service, like a RPC.

CALLER ID:  Known by different names in different countries, this service, available in both analog and digital phones, transmits a caller’s telephone number during the ringing signal.  In addition, a service called CNAM, if available, can also transmit the caller’s name.  Some services block Caller ID for privacy reasons.  The basis for caller ID was invented in 1968 by Ted Paraskevakos, a Greek communications engineer working for SITA and after contributions by many others, has become common on all phones since the 1970s, including VoiP.

CAM:  Computer Aided Manufacturing. See CAE, CAD.

cansCAN:  Slang for “around-the-ear headphones”.  These headphones fully enclose the ears, isolating outside noise and enabling maximum tone and volume, unlike earbuds, which fit inside the ear.

CANONICAL: (a/k/a “normal” or “standard” form) is a (1) mathematical or computer science term that means “the usual way of representing an object”. Because of the way the objects are represented, two or more objects can easily be tested for equality or equivalence of their representations.  In normal English, it means that a programming interface follows established standards.  It is also (2) the name of a British company founded by South African Entrepreneur Mark Shuttleworth in 2004 which specializes in marketing Linux Ubuntu services.


CAPICATOR SYMBOL2CAPACITOR:  a/k/a “cap”.  Devices found on integrated circuits that store electrical energy, kind of like a battery.  Inside a capacitor are two metal plates (connected to polarized  [+ and - ] terminals, like a battery) separated by a non-conducting substance such as glass or ceramic (or, in the case of older ones, toxic fluid, the same brown goop found in old flourescent light ballasts), called the “dielectric”.  Capacitors come in many shapes, sizes and materials.  A capacitor’capacitor smalls storage potential is measured in farads (1 coulomb of charge at one volt; it take a lot of math to decipher this, so don’t ask).  The main difference between a battery and a capacitor is that a battery takes some time to discharge its energy, while a capacitor uses its entire charge almost instantly.  If not discharged, a capacitor will lose its charge shortly and will not hold it like a battery.  This makes a capacitcapacitor diagramor particularly useful for instances where a bright, instantaneous flash is required, such as with a camera flash or laser.  If you remember your high school science course, the basis for the capacitor is generally attributed to a Dutchman named Peter van Musschenbroek, who came up with a device known capacitor diagram2as the “Leyden jar,” the predecessor to the capacitor.  Capacitors are quite common on motherboards and other printed circuit boards and, when they go bad or are “blown” due to electrical surges you can tell because their tops are rounded, possibly leaking fluid, rather than flat and solid, a sure sign that they are causing malfunction!  See TIP#69 and the photos at that location.  In computers, their main purpose is to “filter” alternating current, making it smoother for the circuits and, if it’s burned out, the circuit may not be protected and can fail. 

FOR THE LAST TIME: There is no such thing as a “flux capacitor”.  It was invented for the “Back to the Future” movie.  And, at least right now, we can’t travel backward in time, either.  Jeez!

CAPTCHA:  An Acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart”.  Invented in 2000 by Luis von Ahn, a computer science professor at Carnegie Mellon and sold to Google in 2009, it’s sole purpose is to block unwanted spam, at the rate of some 280 million captchas each day. Why?  Follow the money, of course! For example, an automated spam bot could log on to a website and, in seconds, grab all of the tickets to a concert, then sell them later at a profit, depriving potential customers of the opportunity to attend at the prices intended by the promoter. Or all of the inventory of a popular toy for Christmas.  You get the idea. A typical captcha involves a picture of text, usually with the text rotated, distorted, colored and otherwise creatively altered. Human beings have no trouble reading the text, but simple computer programs can't. A well-written captcha can often keep out even OCR (Optical Character Recognition) programs.  A "Turing test" is any test that attempts to distinguish human beings from computers. The idea of a Turing test is credited to  the computer science pioneer Alan Turing, who first described it in 1950. It’s not perfect, but works much of the time.  An example:

Lately, though, spammers have upped the game, requiring ratcheting up the difficulty and consequently the time (average 14 seconds) required to decipher each captcha, often frustrating legitimate users, sometimes even causing website problems.   One alternative is from Are You a Human, a company that produced a “game” that must be solved to obtain access to a site, by matching “pieces” from one part of the game and dragging it onto another.  Also, Solve Media, which makes the user retype from a list of advertising slogans of some 90 major brands.  There are some 1200 different approaches to creating captchas, and the spammers are working just as fast to get around them.
Captcha game

In 2014, in response to users complaints that the captchas were getting too difficult to decipher, Google introduced “reCaptcha,” a technology that has a user simply click “I’m not a robot”.  If there’s any doubt, a traditional captcha screen will take over.               reCaptcha


CARAT:  The “^” symbol on the keyboard, also called an up arrow, control character, hat, wedge or chevron.  It is a proofreader’s mark, placed just above the base of the line of type to indicate an insertion point for edited text shown just above it.  Also, in mathematics, it stands for “power,” so that 6^10 means 6 to the tenth power.

CARD:  A phrase usually used to describe any printed circuit board inserted into the motherboard of a computer, such as a sound, video or expansion card.  See also, slot into which a card is inserted.  See also, smart card.

CardboardCARDBOARD:  A virtual reality app for Android and iPhone developed by Google which uses a cardboard enclosure with eye holes into which you insert your smart phone to experience virtual reality.  Not fully developed yet, but inexpensive (the viewer only for purchase).


CARD READER:  See “Punch Card”.

CARNIVORE:  An Internet surveillance system developed for the U.S. FBI (along with Echelon) to monitor the electronic transmissions of criminal suspects.  It has been largely discontinued and replaced by other software, partly as the result of charges by the Electronic Privacy Information Center (“EPIC”; See Associations) in 2005 of a lack of safeguards against its misuse.  See also, Echelon; PROMIS; PRISM; Room 641A; Social Networking, Laws, Privacy, How the NSA Does It.

CARPLAY:  A 2014 rebranding of Apple’s iOS in the Car.

CASCADING:  Connecting hardware together in a chain, such as connecting KVM switches or network switches together by attaching one to another (sometimes also called “Daisy Chaining”).  Not always a good idea - e.g. surge protectors shouldn’t be cascaded.  Software:  Anything embedded into anything else, e.g. cascading style sheets.

CASE:  Also called the tower, box, CPU and other names.  Click HERE.

CASES:  See Edge Case.

CASTLING:  Just like a real castle, it is the creation of a private, fortified location for information on a computer network.  See also, Silo, Encryption.

CAT (5, 6, etc.):  Stands for “CATegory” of copper cables used in network and telephone cabling. Click HERE for a full explanation.  See Ethernet for more detailed discussion.

CATASTROPHIC (FAILURE):  Everything fails.  Whether it’s a computer, system, network or component, it is destroyed.  After all, it is a catastrophe.  For less than catastrophic failure, there can be graceful degradation or fault tolerance.

CATCHPOINT:  A web performance monitoring company.

catfish cartoon 2CATFISH: Someone who pretends to be someone much catfish logomore desirable than they actually are by using social media like Facebook, especially for the purpose of  pursuing deceptive online romances.  They pretend to be beautiful, have fulfilling jobs or exciting lives (perhaps as fashion models or neurosurgeons), all to fulfill their need for romance at the cost of honesty, possibly because they don’t believe that they can be loved as they truly are.  A single lie multiplies until entire personas are fabricated, emotions are manipulated and, most often, hearts are broken when the lie is revealed. Often the lie involves facts about a fatal disease, long distance deployment or long-term rehab with the goal of preventing the mark from insisting on a face-to-face meeting with the perpetrator. While this was going on far before the Internet came along See, for example, the 1969 film “The Honeymoon Killers,” or Barney on the TV show “How I Met Your Mother” (who was always trying to pick up girls by pretending to be a producer or a doctor), the term itself is based on a 2010 American TV docudrama which aired on MTV (and which became an MTV show starting 2012) about the truth and lies of online dating, and the assumption that “everybody lies about themselves in online dating”.  A NY City man named Nev Schulman was lured into an Internet relationship with someone who he thought was a 19 year old Midwestern woman.  However, when inconsistencies in her story caused him to investigate, he traveled to Michigan along with his brother and a filmmaker friend, to discover that she was in fact a 40 year old housewife.  It also turned out that she was married, and it was her husband who coined the phrase “catfish”.  In the TV show, the husband explains about the journey of live cod from Alaska to China, and how during their long journey they became lethargic and tasteless, but if they were put in tanks, where they were socially active, they made the journey well.  He compared them to people who play the same role in real life, keeping you on your toes, thinking and guessing serve the same purpose, making your life exciting. I guess the producer renamed the fish after catfish, an ugly bottom feeder.  In one of the most famous examples of a real life online lie is Notre Dame football star Manti Te’o, who, it was revealed in 2013, was tricked into virtually dating a woman who never existed, who he was then led to believe died in a car crash.  Trust me, I couldn’t make this stuff up.  Google it.  Or the Northern California chemistry teacher, Douglas Le, caught in 2016 when identified himself online as Rae Pelletier, a nonexistent creation comprised of a doctored image of an unspecified pornographic actress, and who was actually a trap to trick unsuspecting teenage boys into providing Le with explicit photos and videos on Facebook.  The phrase has also been extended  to describe “Amazon catfish,” those who use made-up identities to hire someone to review a usually mediocre on-line book sold by Amazon, then post on-line five star reviews written by non-existent people who are effectively churning the publishing mill in order to get high Amazon rankings (e.g. Google author Dagney Taggart).

CAx:  The broad term describing the use of computer technology to aid in the design, analysis and manufacture of products.  See CAD, CAM, CAE.

CBS:  Component Based Servicing.  A log file created by Windows used by techs for troubleshooting, it is part of the editable  “servicing stack”.

CD and DVDs: These are types of optical disks, as opposed to magnetic  or other types of disks.  They hold more data, copy more accurately, do not degrade and last virtually forever.  But, unfortunately, not all disks work with all hardware, so read on:

1.  CD (“Compact Disk”):  CD/ROM stands for CD-ROM, which means literally “Compact Disk, Read-Only Memory”.  Originally standardized in 1983 by Sony and Philips, and patented by James Russell in 1970, it is a polycarbonate plastic disk about 4 3/4 inches (120mm) in diameter and 1.2mm thick, on which can be “burned” (written by laser) varying amounts of data (i.e., text, music, video) or about 465 times as much data (about 670Mb minimum) as can be written on a standard floppy diskette.  The ROM  designation on a CD or DVD means that nothing further can be changed on the CD after it has been created, it can only be “read”.  This means that you can see the files saved to a CD/DVD, but since you can’t change any of them, they must first be copied from the CD/DVD to your computer’s hard disk drive in order to edit and then save them.  Of course this doesn’t matter for music and videos.

2. DVD:  Stands for “Digital Video Disk”.  A DVD looks essentially like a CD, but stores at least 4.7Gb of data (about as much as 13 CDs), and up to 17.1Gb (depending on whether storage is single or double-sided or dual layer, see the chart from HP below), and is used primarily for storing music and video files, hence the name “Digital Video Disk”.  There used to be DVD-ROM drives, which didn’t record (just like CD-ROM drives), but they’re not available any more. 

Disk capacities

There is more to know about DVDs than CDs:

>>You should know that “Pre-recorded DVDs” (like movies) may have DVD country code restrictions so they can’t be purchased in one country and played in another. If you’re bringing your DVDs from one country to another, or even purchasing DVDs online, you should be aware of this distinction.

3.  DVDs Can Be Either Writeable (-R) or Rewriteable (-RW):  R disks are, like CDs above, ROM, burned once to store music or video that can be played or viewed, but not changed.  The R designation on a CD or a DVD means that it is a blank disk that can, with the appropriate hardware, be used to create data (R = Recordable) on the disk.  For permanent storage that can’t be changed (like accounting data), this is best.  The RW designation means that it is re-writeable (up to 1,000 times), so that data can be added to the disk at different times until it is complete, or it can even be erased to write new data on it.  Do NOT confuse the writeable/rewriteable designations with the format designations, discussed in Point #4, below.  Both writeable and rewriteable DVDs are available in both +R and -R formats.

4.  DVDs Can Have Different Formats:  To make matters even more complicated, for DVD hardware that plays and records DVDs (as opposed to one which just “plays” the disks), you have two common formats to considerDVD-R (say “DVD-dash-R”) and -RW, developed by Pioneer in 1997, is officially approved by the DVD Forum, a standards group founded by Mitsubishi, Sony, Hitachi and Time Warner, so it has a large group supporting this format. DVD+R and -RW (say “DVD-plus-R”), which premiered in 2002, is approved by another standards group, the DV+RW Alliance, which is supported by Sony, Yamaha, Philips, Dell and JP.  Technically, DVD-R hardware writes data onto the disk using a laser beam, which creates pits (“grooves”), lands (areas between the grooves) and land pre-pits (“LPPs”).  DVD+R uses an improved technology known as ADIP (“ADdress in Pregroove”) that is supposed to be less susceptible to interference and error than LPP and more accurate at higher speeds.  +R also has more robust error management, allowing for more accurate burning, therefore more accurate data transfer and unusable disks, even though it holds slightly less late data.

As you can see from the discussion above, the choice of format really depends on the hardware that is used to either create the DVD or play it, or both.  DVD and combination (“combo”) drives are available that can accomplish all or some of these tasks at varying speeds.  All modern DVD drives can read CDs.  The reason that there are so many formats is because there is no industry standard format (see +R and -R above) and different groups and manufacturers have chosen to support one technology over the other. For more detail, click on this LINK

Originally, it is true that there was some difference between the formats in the way that the -R and +R hardware formats, writes and detects errors. You might create a disk on one computer which couldn’t be played on another.  However, these days, there is little practical difference between the two formats, and they now both pretty much work the same and on both types of hardware.

5. The “DL” Designation: There are a few drives that will utilize what’s known as DVD+R DL disks, which offer a double increase in storage capacity.  But these drives and disks are relatively rate, because the businesses that tend to use them tend to make the move to tape, external or SSD type drives for such data storage.  HVDs and Archival Disks, discussed in Point #9 below, seem to have taken DLs place for hi volume storage. 

>>>So, what’s best?  Due to wider acceptability and ability to play most videos, you can’t go wrong with DVD-R.  DVD+R may be better for data archiving.

6.  Blu-ray, HD DVD:  For movies and video, there are also higher density DVDs such as HD DVD (about 7Gb) and Blu-ray Blu-ray logo(up to 27Gb) which store even greater amounts of information.

7.  Lightscribe Disks:  A type of disk introduced in 2004 by HP and used by a few others (Samsung, LiteOn, LaCie) which, when used with a special Lightscribe optical disk writer, allowed a computer to permanently laser etch images to the label side of the disk.   It never took off and was discontinued by HP in late 2013, so this is pretty much a historical explanation.

8.  DVD-RAM, DVD Slim:  In addition, for a short time, there was also a “DVD Slim” format that never took off.  You almost never see this.  But you may still see some computers (e.g. older Toshiba laptops) with so-called DVD RAM “phase differential” type drives, (both disks and cartridges) popular in the late 1990s because they could be rewritten 100,000 times with high data integrity, but not used often because many movies in the 2000s won’t play on that hardware. ]

9.  THE FUTURECurrently in development by GE are holographic versatile disks, or HVDs, HVD_logowhich can store information not only on the disk surface, but also the entire substrate, to hold three-dimensional holograms that can store data.  They will offer the same write speeds as Blu-ray, but with up to 4 terabytes of storage capacity.

For those who use optical disks for enterprise data storage or backup, in 2014 Sony and Panasonic both announced that they have developed a high capacity next-generation optical disk with an initial capacity of 300Gb.  Called the Archival Disk, it will have the same dimensions as a Blu-ray disk and they claim that it  will be readable for 50 years.

>>>For information about how to burn or rip a CD or DVD, click HERE.

>>>For information about how to copy an ISO file to a flash drive, click HERE.

>>>For photos of various storage media, click HERE.

CDMA:  Code Division Multiple Access” is a digital wireless transmission technology primarily for cell phones, developed by QUALCOMM (originally for military purposes) which is popular because it enables many more people to share the airwaves at the same time without static, cross-talk or interference.  By the way, the “cell” in cell phones refers to the transmitter’s span of coverage.  As the cell phone user moves from one cell or area (span) of coverage, the cell phone is effectively passed on to the next local cell transmitter.  Other popular protocols are GSM, UMTS and HSDPA. CDMA is more popular in the U.S., used by Verizon Wireless and Sprint, although GSM is much more popular in Europe. HSDPA is becoming more popular.

CDN:  Content Delivery Network.  It is comprised of a system of servers that deliver web pages and other web content based upon the user’s geographic proximity to the servers.

CELL:  See, CDMA, above.

CELL PHONE:  Short for cellular telephone, so called bebrickcause it transmits the digital phone signal across microwave towers from one service (“cell”) area to another, as the mobile user travels across the landscape.  In 1982, the FCC formally approved commercial cellular phone service.  The original Motorola phone, a Motorola DynaTAK 8000X, was known as “The Brick,” (because of its shape) is shown at right).  Martin Cooper, a Motorola researcher/executive, is generally considered to be the inventor of the first portable mobile phone (see below).  He made the first call on April 3, 1973 to his rival over the invention, Dr. Joel S. Engel of Bell Labs, while walking on a N.Y. sidewalk. See also, brick.

First SmartphoneRELATED:  World’s first “smartphone” was the “IBM Simon Personal Communicator” (see photo at left).  It went on sale on August 16, 1994.  It had many of the features we associate with smartphones today, including a calendar, ability to take notes, send e-mails and messages, have various apps and could be connected to a fax machine.  But it cost $899, had limited battery life, and was only available to U.S. customers in 15 states.  These factors, and the fact that there was no mobile internet at the time, contributed to its demise after only 50,000 units were sold.

CENTRONICS:  A type of interface (connector at the end of a cable) that is used for parallel cables. The plug has 18 contacts each on the top and bottom and the socket contains one opening with matching contacts. Named after The Centronics Data Computer Corporation, a subsidiary of Wang Laboratories, which introduced the parallel port for computers. Click HERE for photos.

CERF, VINT:  One of the “Fathers of the Internet”.  For more, see Internet, Vint Cerf.

CERN: An international research facility, working at the frontiers of nuclear physics. It was here that the World Wide Web was born and grew, primarily through the efforts of (Sir) Tim Berners-Lee, initially as a way to share information between universities and other research institutes. Shortly after browsers were created for desktop environments -- opening potential Web use to the masses -- CERN made the source code for the World Wide Web  freely available.

CERTIFICATE: Digital Security Certificate or SSL Certificate.  This is a digital computer file or small piece of code that contains (1) information about the authenticity of a user’s identity to verify they are who they claim to be and (2) encryption of the information exchanged while connected so that it cannot be intercepted by anyone else. For another type of certificate see Code Signing Certificate, below.

When you connect to an internet site, your computer checks for a valid certificate which (just like a passport is issued by the U.S. Customs Service) must be issued via a trusted CA (“Certificate Authority,” like VeriSign or Symantec, for example). Every SSL certificate is issued for just one specific server and website address.   Each SSL session always consists of both a public key (which is used to encrypt the information) and a private key (to decrypt it at the other end).  See PKI (“Public Key Encryption”) A “key” is simply an algorithm (formula) that is used to encrypt or decrypt the information.  Most keys support 128-bit encryption, but they can be stepped up or down to handshake with more or less powerful computers.  After there has been a “handshake” between the two computers and a session has been initiated, a secure link is established for that session with a unique session key, and communications begin.  You can tell if it is a secure connection by the designation “https://” in the URL, or a padlock on the browser page or the like.  The highest level of security, EV [“Extended Validation”] certificates cause the address bar to turn green in high security browsers, assuring the absolute highest level in customer trust.  Certificates are used for the purpose of securing information sent between computers or servers (like shopping websites), securing communications over a corporate intranet, securing information over mobile devices and securing e-mail.  It looks about like this:


More detail:  While he was working for Netscape, Dr. Taher Elgamal created SSL (Secure Socket Layer) technology, which became adopted as a standard web technology known as TLS (Transport Layer Security) by the Internet Engineering Task Force.  The certificate credentials created by SSL/TSL are employed to establish and positively validate a user’s identity on the Internet, most commonly used for online shopping and downloads.  There are two types:  “Soft” (embedded in web browsers, most common) and “hard” (smart cards used with special readers).  Each certificate contains a chunk of information (often stored as a text file, see above) that is used by the SSL protocol to establish a secure connection.  Certificates contain information about who it belongs to, who it was issued by, a unique serial number, valid dates, and an encrypted fingerprint that can be used to verify the contents of the certificate.  In order for an SSL connection to be established, both sides must have a valid security certificate. The are loaded by the servers when the connect.

Certificates may be “self-signed” (generated for internal, usually corporate, purposes and not by a CA), “domain validated” (as the name implies, the only verification is that the applicant actually owns the domain (website), and not, for example, that it is a valid business entity, or “fully authenticated”, meaning that a complete verification process has been performed on the business and the domain.  There are also other types of certificates available, such as “wildcard” certificates (allow full SSL security to any host of a domain, as domain names are often used with any number of different hose suffixes), “SAN” [Subject Alternative Name] certificates (which allow more than one domain to be added to a single SSL certificate), “code signing” certificates (see below - which assure that the software you have downloaded has not been tampered with en route), and others.

In 1995, NIST and NSA (see Associations) developed a U.S. standard for digital signatures known as SHA (Secure Hashing Algorithm).  Starting on December 31, 2015, most browsers, programs and O/Ss began rejecting SHA-1 certificates and requiring the more secure SHA-2 and SHA-3 certificates.  December 31, 2016 was agreed to be the “final” date that SHA-1 wil be accepted for affected certificates.  This will give site developers more work, as many web sites will not get through if their certificates aren’t up-to-date.

It can be expensive and time consuming for businesses to get digital certificates, particularly for software downloading, but is becoming a requirement for online protection.  For example, when you download software, have you noticed the window that asks you whether you want to continue, because there isn’t a security certificate for that software?  It’s usually O.K., but you’re being told it’s at your own risk.

When certificates are stolen by hackers, as they were in September, 2011 from Dutch security firm DigiNotar, the stolen credentials were used by hackers to eavesdrop on the Gmail, bank and credit card accounts of some 300,000 people and perhaps pose as banks or shopping websites in order to steal cash from those users. For more, see the SECURITY page of this site.


CES logoCES:  Consumer Electronics Show. An annual event held each January since 1967, and since 1998 at the Las Vegas Convention Center, sponsored by the Consumer Electronics Assn. (see Associations).  However, unlike COMDEX, below, it is not open to the public.  CES hosts previews of new and developing products and upcoming product announcements and has been the venue for many famous introductions, such as BluRay, tablets, DVDs, HDTV, VCR, Ultrabooks and the like.  The third large show is INTEROP.

CES: See, Consumer Electronics Show.

CGA:  See, COLOR, also VGAColor Graphics Adapter, introduced in 1981 by IBM, capable of rendering 4 colors at a resolution of 320 pixels horizontally by 200 pixels vertically.

CGI:  Common Gateway Interface is a protocol (language) that allows web pages to run a program (called a “script”) on a web server.  Common examples are forms, counters and guest books.  CGI scripts are sometimes kept in directories called CGI-BIN, which are separate from the other directories on the server; others allow scripts to be run from the CGI-Local directory.  CGI programs are often created using PERL, Practical Extracting and Reporting Language, which costs nothing and is free to distribute, thus has the advantage of a large population of contributing programmers.

ChampillionCHAMPOLLION, JEAN-FRANCOIS:  1790-1832, the “Father of Egyptology”.  The French philosopher who ultimately solved the riddle of the Rosetta Stone, a stone tablet written in 196 BC that contained three different languages of essentially the same text (Egyptian heiroglyphics, ancient Greek and Demotic script).  All were decoded except the heiroglyphics until Champollion, competing against noted Egyptian historian Thomas Young, determined that they were a combination of logographics (combinations of an alphabet and single characters that represented a word or phrase). Unfortunately for him, Young was a popular and noted Egyptian historian who repeatedly disputed his findings in public, even when shown irrefutable proof, such that other Egyptian experts wouldn’t give him the credit she was due until many years after his death.  See also, encryption.

CHANNEL:  See Spectrum.

CHAOS THEORY:  This term is mentioned within several definitions in this site.  It is a mathematical concept, with links to many other disciplines, which attempts to explain what appear to be disordered, apparently random conditions on the basis that the initial (so-called “linear”) condition, which appears to be predictable, can be changed by random events along the path to its intended consequence.  That is, a predictable system can be changed over time.  This is known as the “butterfly effect”.  A butterfly flapping its wings in Oregon may cause a tsunami in Japan.  In other words, disorder is limited.  In fact, there are four forces that chaos theory posits can intervene to cause predictable occurrences:  They are (1) sensitivity to the initial conditions, (2) topological mixing, (3) density of periodic orbits and (4) strange attractors.  Click HERE for more about these complex explanations.  The path between order and disorder can occur in surprising ways, and this is what chaos theory is all about.  Another important element of chaos theory is “fractals” which are never-ending patterns, endlessly repeating in loop.  Most credit the concept as first being proposed by Henri Poincare in the late 1800s and then expanded and made popular by Edward Lorenz in the 1960s.

CHAP:  Click HERE.

CHARACTER:  Any letters, numbers, symbols, glyphs or other representations that can be entered into a computer via keyboard or other input device.  See also, Wild CardFor interesting information about the derivation of such symbols as the at (“@”), tilde (“~”), pipe (“|”), carat (“^”), ampersand (“&”), bracket (“[ ]”), braces (“{  }”), parenthesis (“(  )”), angle brackets (“<  >”), octothorpe (“ # “), asterisk (“ * “), virgule (“ /”) backslash (“ \ “), pilcrow (“ “), section sign (“ ), interrobang (“ Interrobang copy “) [my personal favorite],  EM-Dash, EN-Dash (“---”) and other computer-related symbols, see those definitions within the  computer glossary.  For more characters, click HERE.

CHAT:  The ability to exchange on-line text messages. See SMS, IRC, MMS.


CHAT ROOM:  A site or part of a website where users can communicate with each other by typing messages over the Internet in real-timeTypically, a chat room is devoted to a particular topic or group of users.  America On-Line, for example, has defined chat rooms for common interests such as music, movies, etc.  Most chat rooms require users to choose a user name and password to log in and out to the room, so that the other users are alerted to their presence and their name.  Users can choose to post or just listen to the conversation.  Also, some sites allow users to participate in “PM” or “private message” separate and apart from the entire group so that their messaging will be one-on-one.  Most chat rooms are part of a site or service like AOL or Reddit and don’t require any special software.  Some types of chat, such as Internet Relay Chat (“IRC”) may require the user to download (usually free) software from the Internet to participate. 

NOTE THAT chat rooms differ from “forums” and “bulletin boards” in that those venues do not offer real-time communication and merely allow users to post messages which can be responded to by other users of the group at a later time.  However, forums generally allow messages longer than a line of text, and often have “threads,” which are topics or questions which followed a single issue, which can also be replied to by an unlimited number of people. And, if they become too involved, they may then be divided into  “subforums” each of which is about a sub-topic, which is usually assigned by a human “moderator,” who oversees the forum and who also can determine when a discussion is “closed” (for example, when it is about a problem that has been solved). 

CHECK DISK:  A Windows utility which performs hard disk analysis, used often by computer techs.  It can be run either as a basic version from within Windows (Computer>Disk>Properties>Tools>Error Checking) or from a DOS command line (chkdsk.exe; with advanced switches).  It is used to scan the computer and locate and fix file system errors and bad disk sectors; you can tell if you have a failing hard drive.  So exactly what does it do?  It has 5 stages, the first three of which are considered major, the second two optional (you must select both repair options for the scan) and can take from only a few minutes up to an hour or more to complete.  Once complete, a log report is available both on-screen and in the Application Event Log as Event ID 26212.  Stage 1 examines each “file record segment” in the MFT (Master File Table). In an NTFS volume, for example, each and every file and directory on the volume is identified by a specific file record segment in the MFT.  Stage 2 examines the indexes (directories) on the volume for existence, internal consistency and accuracy.  Stage 3 examines and confirms the security descriptors for each file and directory.  Stage 4 verifies all clusters in use.  Stage 5 verifies unused clusters.  Starting with Windows 8, Microsoft has redesigned the utility by introducing a file system named ReFS.  It is run every time the system starts up, but can be run manually by right-clicking on the drive, selecting Properties, then Tools and then the Check button.  Follow the prompts to see if the drive requires scanning.  Click HERE for a little more explanation.

Check Point logoCHECK POINT SOFTWARE TECHNOLOGIES LTD:  An Israeli software company Gil shwed photowhich was one of the originators of modern Internet security.  It was formed by Gil Shwed, a coding prodigy, when he was 24 in 1993.  Check Point created the first firewall using stateful inspection, the most widely used firewall technology used today.

CHECKSUM:  One of the original and oldest error-detection schemes for Internet transmissions.   Each transmission is accompanied by a number representing the number of bits in that transmission, so that the recipient can then compare it to verify that the same number of bits transmitted have actually arrived.  Literally, checking the sum at the receiving end with the sending end.  Often, if you download a program and receive a “checksum error” message, it means that you didn’t get the entire download, or it was corrupt. You can stop reading here, unless you want to get more technical...

Checksums are also used for other verification purposes, such as the Luhn algorithm in IEMS numbers.  Don’t confuse this with public key encryption, which is much higher security than simple verification.  Checksums are far less secure, used for verifying transmissions and preventing human data entry error (i.e., someone types in the incorrect ID or serial number).  Fixing a checksum error generally involves re-downloading or attempting to re-install an application, although there can be other causes and therefore other cures for checksum errors.

Another similar verification method is CRC (non-binary Cyclic Redundancy Check) which instead uses polynomial division (the manipulation of “real” numbers known as “monomials” into something more complex to determine a value (usually 16 or 32 bits long), making it even more accurate, because if even a single bit is incorrect the CRC will not match up.  This is the basis for Reed-Solomon (RS) codes that detect and correct multiple random symbol errors.

So how is a checksum actually determined?  First, remember that a byte is made up of 8 bits, each of which can be in one of two states.  That’s 256 (2 to the 8th power) possible combinations.  (255, since the first byte combination would equal zero, which would be impermissible.) Considering this, if the sum of the other bytes in a packet transmission is 255 or less, then the checksum will be that exact value.  If it’s more than 255, then it will be the remainder of the total value after it has been divided by 256.  Let’s try an example:  If the packet transmission is a total of 2,750 bytes, then it’s more than 255, so you have to divide that total by 256, which would be 10.74, which we round off to 11.  Then we multiply that 11 times 256 for a total of 2816.  Deducting the 2816 from the original 2750 bytes, we calculate a checksum of 66!  If you’re lazy, you can click HERE for a free checksum calculator.

HELPFUL REPAIR NOTE:  One of the most common startup errors is a BIOS  checksum error.  In fact, it usually is the result of a failing battery on the motherboard, causing the BIOS to return this type of error.  More often than not, replacing the battery solves this problem.

CHERRY BLOSSOMING:  The inflating the number of Twitter “Tweets” or Facebook “Likes,” making a person or company appear to be much more successful than it actually is. For more, see Twitter.

CHICKLET:  Named after the square white (and later, colored) pillow-shaped chewing gum pieces (see right), it has at least two computer meanings.  First, with reference to computerchicklet keys on the keyboard, chicklets are each key, particularly “island” keys on a laptop, because they look like chicklets.  Second, an on-screen button that usually has a logo for a feed or blog, allowing users to easily subscribe by clicking on the button.  For more see keyboards.

CHILD:  Any subdirectory below the root directory of a driveA directory above a subdirectory is a parent directory.

CHIME:  See Amazon Chime.

CHINESE ROOM:  A “thought experiment” proposed by John SearleJohn Rogers Searle (1932 -   ), an American Philosopher at UC Berkeley, intended to debunk the idea that a digital computer program can give a computer a “mind” in terms of understanding or consciousness, regardless of how intelligently it may behave. It was his reaction to the position (known as “functionalism” and “computationalism”) of some AI proponents that the human mind is itself an information processing system, much like a computer.  In the Chinese Room construct, a human who knows no Chinese is locked in a room with only a set of rules, in English, that will allow him to respond to questions posed by other unseen humans who understand Chinese by correlating his English responses into  Chinese characters which he doesn’t understand.  This convinces those who slide the questions under the door to the room that he does in fact understand the questions, even though he really doesn’t.  Searle posits that this is  the same thing as an AI digital computer, which may appear to pass the Turing Test, but which is not actually intelligent because it is only simulating human intelligence (i.e. the ability to understand Chinese and intelligently respond in kind).  Searle breaks down the simulation into what he calls “Strong AI” (literal understanding of Chinese, which may not even be possible) from “Weak AI” (merely simulating or appearing to understand Chinese).

CHIP*The “brain” of your computer (a/k/a the processor) - See also, CPU, below.  In a broader sense, it is shorthand for “chip” or “microchip,” a semiconductor silicon wafer embedded with circuits and electronic components, which are used in anything from cars to appliances to computers.  While chip making was revolutionized when scientists purified silicon in 1950, it is now predictable that, when silicon chips become smaller than 7nm, new media will have to be developed in order to build more powerful computers which will continue to perpetuate Moore’s Law.  For other types of chips that are being developed for the future, see #7 in the Computer definition, below.  For other chips, see IC Chip. For a discussion about semiconductors, chips and integrated circuits and their invention, click HEREThe name came from the 1971 introduction of the 4004 four-bit processor by Intel, which it called “a computer on a chip”.

CHIPSET*The chips on a motherboard that control the functions and features of the board itself, such as determining how much memory you can use with it and what type of processors can be inserted.

CHIPTUNE:  a/k/a chip music or 8-bit music.  Synthesized electronic music produced by the sound chips of vintage computers, video game consoles and arcade machines.  The equipment is readily available, inexpensive and attractive to underground tinkerer types.  These became popular in the 1980s along with the popularity of electronic dance music and full scale dedicated synthesizers.  Click HERE for a brief history of chiptunes.

CHROME:  See, Google Chrome.

CHROMEBOOK:  So, if you’ve been watching the avalanche of 2013 TV ads for the Google Chromebook at a mere $249, wondering what it’s all about, hereChromebook ad it is:  It looks like a laptop computer (no detachable screen like a pad), is manufactured by Samsung, Acer and HP and sports a dual-core processor and 2Gb of RAM, along with 2 USB ports and an SD memory slot. A pricier Google-designed “Pixel” is also available.) Because it uses the Chrome browser and operating system, it is primarily intended to work when connected to the Internet (through Wi-Fi or 3G).  While you can do a limited amount of word processing and office work without being connected to the Internet, it really won’t work without the intended cloud apps like Google Docs.  And, while you can download or transfer files or software onto the computer, it’s no guarantee that they will be compatible with the system - you may be able to get it on there, but it may not install or work.  Also, it’s not upgradable.  So it looks like a laptop, but has some limitations you should check out before purchasing.  Make sure it’s right for you, don’t get “scroogled” as the Microsoft counter-ad says.  The price is inexpensive, but it’s no true laptop.  UPDATE:  It’s been five years and the Chromebook has been upgraded for work - the Chromebook 13 was introduced in October 2015, suitable for mainstream enterprise use (with upgrades).

SO, IF THEY’RE NOT THE SAME, WHAT’S THE DIFFERENCE BETWEEN A LAPTOP AND A CHROMEBOOK?  First the Chrome Operating System is essentially a Chrome broswer configured to look like a Windows desktop.  Still, it’s essentially a smart phone dressed up with a larger screen and keyboard.  The apps aren’t the same:  You can’t download apps and those you use appear as a tab in the Chrome browser.  Local storage is extremely limited, usually to the space on an SD card, such as 16/32 or 64Gb.  And you can’t just plug in a printer into a Chromebook, you’ll have to use Google Cloud Print and have a cloud-ready printer or some other work-around.  But it costs lots less and, for those who only need a simple internet appliance, it can still be useful.  But it’s not a substitute for a laptop, even though it truly looks like one.

CHROMECAST:  See, Google Chromecast.

CHANNEL:  Generally, referring to computers, a reference to the retail sales distribution chain for computers, particularly the use of VARs, which sell computers with added customization to the end users.  Secondarily, technologically, a path for data [i.e. 32-bit graphics systems contain 4 “channels” (red, green, blue & alpha (blending mask); or “fibre channel” path for serial data transfer.]

CHEF:  Popular cloud server-management software.  See Puppet for more.

CID:  Caller ID.  The telephone number of a caller.  See screen pop.

CIDR:  Classless Inter-Domain Routing a/k/a subnetting.  See, IPV.

CIO:  Chief Information Officer. Usually found in larger companies, the CIO is responsible for all of the IT issues (planning, implementation, operation) within the organization.  Sometimes called the Chief Technology Officer (CTO); also CISO, the Chief Information Security Officer, primarily responsible for data security.

CIPHER:  See, encryptionTo encode into secret writing.  There are various types of ciphers, including stream cipher and block ciphers.

CIRCUIT: Broadly, a path between two or more points along which an electrical current or a signal can be carried.  A circuit must be, by definition, circular, in order to complete its path.  That is, it must begin and end at the same point so as to be continuous. Example:  When you connect a wire to the top and bottom of a battery and the in and out ports of a motor, a continuous circle of electrical energy is created, powering the motor.  When the circuit is broken, by a on/off switch for example, the motor stops.  If there is an overload, a circuit breaker can be “tripped,” also breaking the circuit, preventing any damage to the motor.  Click HERE for more discussion.  Many circuits and sub-circuits can exist in the same system, as they do on printed circuit boards (PCBs) and semiconductor chips.


Cisco logoCISCO:  One of the world’s largest technology companies, specializing in networking and telecommunications hardware and services.  Since 1995, its CEO has been John Chambers.  The name Cisco was derived from the city of its offices, San Francisco, which was why it was originally shown in lower case. Also, the Golden Gate Bridge design on the logo.  Now it’s Cisco Systems.

John Chambers
Cisco logo

CITRIX:  Sounds a little like Cisco (above) but it’s unrelated.  It’s a Florida company started in 1989, originally named Citrus, later changed to Citrix (a portmanteau of Citrus and Unix).  If you’ve had reason to connect remotely to your desktop or have a help desk control your computer, it’s often Citrix software.  It’s more: Citrix is involved in server virtualization, SaaS and cloud computing, as well as desktop virtualization.

CLAMP TIME:  Also, CLAMP VOLTAGE.  See, SURGE SUPPRESSORS.  A measure of the voltage threshold and the time threshold (in milliseconds) necessary to trip a surge suppressor.

Jim Clark photoCLARK, JIM:  James H. Clark.  Along with Marc Andreesen, co-founder of Netscape, also Silicon Graphics, Inc., and several other Internet companies.

CLASSES OF IP ADDRESSES:   There are three classes of IP addresses:  Class A (supports 16 million hosts on each of 126 networks).  Class B (supports 65,000 hosts on each of 16,000 networks).  Class C (supports 254 hosts on each of 2 million networks).  See Public vs. Private, and iPV for more detail.

CLEANING:   This is beyond the scope of this type of glossary, but mentioned only because general janitorial or home cleaning isn’t sufficient for clean computer rooms or even home or office computersAirborne contamination and particulate migration must be considered, and ISO Standard 14644-1 must be adhered to. Some advice for cleaning monitors and keyboards is in FAQS.

CLICK: The act of depressing either the any of the buttons on a computer mouse one or more times in order to select an option on the screen.

CLICK FRAUD: Many advertisers pay for their web advertising on a “per click” basis.  That is, they pay a small charge, say a nickel, each time a computer user clicks on their ad.  Unfortunately, some unscrupulous marketing companies use software or cheap non-U.S. workers to generate hundreds of “click-throughs” an hour, generating huge dishonest profits while producing absolutely no sales.  And it’s not only the marketing providers who do this:  Some firms will hire them to waste their competitors’ advertising money.  See also, cherry blossoming.

CLICK LAUNDERING or CLICKJACKING: Seejackingand SpywareA practice of artificially adding clicks to website ads.  An example would be that used by RedOrbit and HelloMetro, against which Microsoft filed lawsuits in 2010.  They directed traffic to their own servers, removing the identifying information, then replacing it with information making it look like the hits came directly to the site in question.

CLIENT:  A subservient computer which is dependent upon a server computer.  The client (sometimes called a “dumb terminal”) is a device that is not capable of running its own stand-along programs, so it relies on a (usually) separate computer over a network.  A so-called “Thin Client” is a computer which is designed to be especially small so that the bulk of the data processing occurs on the server.


Clippy 2CLIPPY:  Intended by Microsoft to be an assistant in early versions of Microsoft Office, it was officially discontinued in about 2009.  Users found it annoying (whole blogs about it), others made fun of it (“I see you’re trying to write a ransom note, can I help you?!”) and even Microsoft showed some video humor when it killed off Clippy when it introduced Office 2010.  Click HERE for more interesting history.

CLIPPER CHIP:  A chipset that was developed and promoted by the U.S. Government to be used by telephone, computer and other electronics manufacturers, so that the Government would be able to decrpyt possible terrorist transmissions.  Announced in 1993, due to a tremendous backlash by consumers and manufacturers, it was withdrawn by 1996.  Since that time, the U.S. Government has attempted to propose Clipper 2 and Clipper 3, which stipulate that the Government be able to recover any keys exported outside of the U.S., but neither plan has met with any real success.  The U.S. government, however, does possess the ability to hack into cell phones through their GPS chips and computers and other smart devices through other intrusive means.  See Privacy for more discussion.

CLOCK:  The speed (“rate”) at which a computer microprocessor executes instructions.  Measured in Mhz or Ghz, every computer contains an internal clock that regulates the rate at which instructions are executed - the faster the clock, the more instructions the CPU can execute per second.  The CPU requires a fixed number of clock ticks or cycles that it can execute per second.  Not quite the same as the BIOS or Real Time clocks on the computer that keep track of the day, date and time when it is turned off. In early computers, techies used to “overclock” the computer in order to increase it’s speed (not a good idea).  Incidentally, on a multi-core chip, the total clock is not equal to simply multiplying the number of chips times the clock speed, it is less.

CLOCK LINES:  The conductors that carry the clock signal to various parts of the computer.

sheep reversedsheep1CLONE:  Commonly means “copy”.  (Like “Dolly” the sheep was cloned om 7/5/96.)  In the computer world, your can “clone” several things:  For example, (1) to “clone” a CD or a DVD means to make an exact copy.  To “clone” a computer drive (2) means to make an exact (bootable) copy as well.  Not just backing up the data from the drive, but also the operating system, hardware drivers, boot sector, etc.  Everything.  There’s no connotation about whether the copying is legal or illegal.  Computers themselves (3) can also be “cloned”.  Back in the 1980s, there were lots of companies which sold what were called “PC clones,” meaning that companies reverse-engineered and/or independently created personal computers which emulated and performed like the (first and original) IBM PC, legally.  The first actual PC clone was made by “CDC” (Columbia Data Products), a Maryland company, which released it’s “MPC 1600” in 1982.  But CDC wasn’t able to successfully produce it in any quantity, and went bankrupt.  Also in 1982, Compaq Computer (a Texas company started by a group of former Texas Instruments employees) introduced its own clone, which was quite successful and was produced in one way or another until Compaq’s merger with HP in 2001.

CLOUD:  Click HERE for an explanation of Cloud Computing.  See also SaaS.

CLOUDLETS (a/k/a Follow Me Cloud, Mobile Micro Cloud):  A cloud datacenter located at the edge of the Internet which supports interactive mobile apps.  The “edge of the Internet” is where a network infrastructure connects to the Internet, acting as a gateway to connect to cyberspace.  It is the middle tier of mobile devices, i.e. mobile device> cloudlet > cloud.  The term was first coined by M. Satyanarayanan at Carnegie Mellon U.  While most mobile services divide their apps between the front end client program, which traditionally offloads its functionality to the back-end server program (which is typically hosted at the cloud data center for speedier processing), cloudlets address the large separation between the mobile device and its associated data center and the built-in high number of network hops, by establishing a single network hop between the outer edge of the enterprise network to the Internet, to achieve better scalability, elasticity, higher bandwidth and lower latency.  This is achieved by placing the offload infrastructure in a cellular base station or even a LAN connected to a set of Wi-Fi base stations.  This is particularly useful for gaming apps , augmented reality apps (like Pokemon Go) and personal digital assistants like Siri and Google Now, where require end-to-end latencies of less than 16ms

CLSID:  Stands for “Class ID”.  This is kind of like a “social security number” for software (or one if its components), a unique ID that is stored in the operating system registry allowing the software to be identified and, therefore, to operate.  It is generally a large (128 bit) number that is displayed, between brackets, something like this: {AE&AB96B-FFSE-4dce-801E-14DF2C4CD681}.  See REGISTRY for further information about CLSIDs.

CLUSTER COMPUTING:  Using a group of computers to solve a single problem.  Clusters may be distributed, grid, parallel or any other configuration, but the purpose is always the same: To take advantage of the massive group computer resources to solve a complex problem in less time.

CMC:  Computer Mediated Communications. See Texting.

CMDLETS: (pronounced “command-let). Lightweight commands used in the Windows Powershell environment. They always have the “.ps1” extension.

CMOS:  (1) Computer Minimum Operating System. A small amount of memory on a computer’s motherboard that maintains the time, date and other basic system setup settings, maintained by a battery mounted on the board.  See FAQ #22. (2) Complementary Metal Oxide Semiconductor, an integral part of a digital camera sensor.  See Digital Cameras.

CMS:  Content Management System.  This is a way to build, organize and generally manage web page content right on the web, as opposed to developing a page in HTML, then FTPing it to the server. FaceBook is CMS.

CnC:  Command and Control Server, those computers which spread spam in a botnet.  See SPYWARE.

CNR:  A motherboard slot, like AGP and PCI used in the ATX family of motherboards supporting audio, modem and networking subsystems.   Developed by Intel, it is an acronym for Communication and Networking Riser.

COAX:  A type of cable (short for “coaxial”) that is generally used for television/internet and antenna cable, characterized by a center copper wire that is surrounded by plastic insulation and then a grounded shield of braided wire.  Standard coax is usually called RG-6, while quad shielded cable (4x shielding power) is called “quad-shield”  or RG-59.  Older computer cable, 10 Base T, is also coax.  Click HERE for photos of coax cable and connectors.

Cobol LogoCOBOL:  Acronym for “Common Business Oriented Language,” once one of the most widely used programming languages in the world, although it was developed in the late 1950s, particularly popular for business applications that run on large computers.  Because it excels in processing large volumes of data, it’s used in industries that perform “batch processing”, like credit card companies, banks, the Federal Reserve Bank, the IRS and security and screening purposes like immigration and terrorist checks.

COAX:  A type of cable (short for “coaxial”) that is generally used for television/internet and antenna cable, characterized by a center copper wire that is surrounded by plastic insulation and then a grounded shield of braided wire.  Standard coax is usually called RG-6, while quad shielded cable (4x shielding power) is called “quad-shield”  or RG-59.  Older computer cable, 10 Base T, is also coax.  Click HERE for photos of coax cable and connectors.

CODE:  Generally refers to a line of alphanumeric (letters and numbers) instructions that tell a computer to do something, character by character (see “The Great Semicolon Debate”); a computer program consists of many “lines” of code.  Those who write code are called “coders” or sometimes “programmers”.  Code is executed (run) by a computer after being compiled into machine language it can understand.  (see Programming).

CODEC:  An acronym for compression/decompression, a codec is a specialized computer program that encodes or reduces the number of bytes consumed by very large programs.  Files encoded with specific codecs require the same codec for decoding.

CODER:  Short for a computer programmer, i.e. one who writes code (see above) to create programs.  See also, Topcoder.

CODE SIGNING:  A technology that uses digital certificates (a/k/a software signing certificates) and the public key infrastructure (“PKI technology, issued by a CA) to sign program files so that users can authoritatively identify the publisher of the file and verify that the file hasn’t been tampered with or accidentally modified. An SSL certificate is not the same thing, and cannot be used for software. Each type of program has different code types, as created by the software developer, some more secure than others.  For example, the Stuxnet virus code was purportedly propagated with what were at the time valid certificates issued by VeriSign.  For example, Windows .NET programs have a special “self-signing” method (see Certificates), which means that no trusted CA is involved.  So, there’s no revocation method, either, which would make the compromise of the key insecure.  In such cases, developers combine what is known as the “Strong Name” mechanism, which has more traditional code signing technologies (like Microsoft’s Authenticode).  In the .NET case, the .NET Framework SDK Strong Name Tool8 (sn.exe) serves this purpose.

Colecovision logoCOLECOVISION:  One of the earliest video game consoles introduced in 1982.  While the company went bankrupt in 1982, it was reformed in 2005 and has announced its first new console in decades, the Coleco Chameleon, which is a reversion to game cartridges, reminiscent of the Retro VGS, a game developed and marketed by Retro Video Game Systems, with which Coleco is teaming for the new console.  See also Wii, Playstation, Sega.

COLOCATION (“COLO”): A facility which is a data center where businesses can rent space for their computing hardware (like servers) and where the provider not only provides the building, but also the power, cooling. bandwidth (broadband internet service) and physical security,.  Each tenant provides its own server(s) and storage.  See also, MMR, POP Rooms, Ping Power Pipe.

COLOR:  The number of colors that can be viewed over a computer monitor varies by the computer hardware on the motherboard, the video card/board, the monitor and the web browser/program.  See, in this Glossary, the RGB, CGA and S-Video color models.  The number of colors that can be displayed, theoretically, range from 256 to 16,777,216 (standard 24 bit) colors, or even more.

ComcastCOMCAST: The nation’s largest cable provider, headquartered in Philadelphia and doing business in 39 states and DC.  Also, acquired a majority stake in NBC in 2011.  The name is a portmanteau of the words “communication” and “broadcast.”  Started in 1963 by Ralph Roberts (who remained as Comcast’s president) and others as American Cable Systems.  In 2011, rebranded to Xfinity to include the triple play combination of Internet, telephone and TV.  The Comcast name is still used for corporate accounts.  Also includes the Smartzone communications center for e-mail accounts.

Comdex logoCOMDEX:  An acronym for Computer Dealers Exhibition.  A computer expo held in Las Vegas each November starting in 1979 and last held in 2003.  It was one of the largest and most popular computer trade shows in the world, running for a “geek week” where industry leaders made keynote speeches and new products were introduced.  Now the big show is the CES, see above.

Comic-Con logoCOMIC-CON: Geeks love computers.  They also love Comic-con charactercomics.  And they attend not only Star Trek conventions but also comic conventions.  The bigger the better.  Comic-Con denotes any of a number of “comic book conventions”, the largest of which is the annual fan convention held in San Diego since 1970.  Attendees sometimes dress up as their favorite characters (right) and sell and trade both comics and memorabilia. See also cosplay. or CMD.exe: A 32-bit MS-DOS run-line command known as the “command prompt” that is used to run certain disk and file maintenance and network functions in DOS.  See, command line, below,

COMMAND: An instruction to the computer to do something.  It can be a text command line or a run line, or else a keyboard command (e.g. Shift + F8 makes type bold) or even a mouse command from a menu.

Apple Command SymbolAPPLE COMMAND KEY:  Similar in function to the Windows key and sometimes the CTRL key (depending on the version of the Apple keyboard), it is a special function key used to translate menu commands directly to the keyboard, because when pressed in combination with other keys it would select the corresponding menu command.  Developed by Andy Hertzfield, a member of the original Apple development team, Steve Jobs fought the symbol (which has become alternatively known as the Gorgon loop, the splat, the infinite loop, a place of interest sign (in Unicode) and (in Sweden, a noteworthy attraction in a campground) as designed by Apple’s Susan Kare (see icon), because he wanted to use an Apple symbol, while Andy Hertzfield believed that there were just too many Apples on the screen already.  To this day, the command key symbol has remained, although on some Apple keyboards, both that and the Apple symbol are printed on the same key.  Used as a meta key for Linux.

COMMUNICATION:  The sending and receiving (i.e. “communicating”) of a signal (e.g. words, electronics, magnetics, even behavior) between two or more parties (humans) or devices (e.g. telephones, computers).

COMMAND LINE:  Used to run a DOS command.  A run line is used to run a Windows command.

COMBINER:  See, SPLITTER. A splitter which operates in both directions.

Compaq logoCOMPAQ:  A computer company founded in 1982 by Rod Canion, Jim Harris and Bill Murto, formerly from Texas Instruments, which was one of the first to legally reverse engineer the IBM PC (see Clone).  It sold its computers through resellers in order to avoid conflicts with IBM.  It was acquired by HP in 2002.  The name has been said to mean “Compatibility and Quality,” but history records that it was just one of the names chosen from a list compiled by the Ogilvy and Mather ad agency at the time.

COMPILER:  A program which converts the source code of a program, created and readable by humans, into the binary object code for that program, executable by a computer’s CPU, although in a broader sense, a compiler is any program which converts code from one thing to another. The machine language for a particular computer is tied to the architecture of its CPU.  A programmer can create source code using a “high level” programming language such as C++, Python, Java, Fortran, Cobol, Pascal, etc. then the compiler (also sometimes called an “interpreter”) translates it into machine language.  For more information, see the discussion at source code and object code.

Z = 0;

X = 3;

WHILE X ~= 0

    Z = Z+Y;

    X = X - 1

Y = Z;




ADD R3 R2 R3

SUB R0 R0 R1














COMPLIANCE:  As governments and technology groups (see Associations) increase their grip on secure technology, various types of “compliance” are being mandated, usually through some type of audit.  But the definition for many of these terms is confusing and often used interchangeably: 

The two fundamental processes which take place during a compliance audit are Attestation and AssuranceAttestation - Audits such as ISO-27001, SOC-2 and FIPS show that an organization has validated (or sometimes that the enterprise has self-represented) that an enterprise’s claims are true, after an examination of processes, product codes and other pertinent evidence.  Assurance:  This is more in-depth than Attestation, which relies mostly on the enterprises’s representations.  Type II Assurances, such as HIPAA or ISAE-3000 are much longer audit processes, often taking place over a 6 month period or longer, and using outside auditors. 

Once the audit is completed, compliance can be described by various terms:  Compliant - the organization has aligned its processes and controls with the requirements of the regulation.  Certified:  The governing body conducts its own audit and issues a certificate certifying compliance.  This isn’t always available, such as HIPAA, which only allows compliance, but not certification.  Validated:  This takes regulation a step further, requiring validation for the authenticity of certain certified components.  An example would be the FIPS 140-2 validation for certified encryption modules, meaning that the code inside the encryption modules has been reviewed and then certified by the U.S. Government.

A tip of the hat to Dave Packer, VP, Corporate and Product Marketing, Druva Corp., in his 8/30/2016 Network World article, greatly reduced and summarized in this definition.

COMPONENT VIDEO:  Click HERE for information.

COMPOSITE NUMBER:  Any number not a prime number.  See prime number for more.

COMPOSITE VIDEO:  Click HERE for information.

compuserve logoCOMPUSERVE:  a/k/a CIS (“Compuserve Information Services”) was started in 1969 and was arguably the first commercial online service in the U.S.  It was originally created as a subsidiary of the Golden United Life Insurance Co. to provide in-house processing support and also to develop into a separate business for the computer time sharing industry, then in its infancy (e.g. dial-up connections). CompuServe was immensely popular through the 1990s, offering e-mail and web services at a set hourly rate.  However, AOL and other providers which offered service at an all-inclusive low monthly rate drove CompuServe out of business, and AOL eventually acquired CompuServe, effectively putting it out of business on 7/1/2009.  An interesting aside:  In 1992, CompuServe acquired Marc Cuban’s company, MicroSolutions, making Cuban a millionaire. This was way before the TV show “Shark Tank”.


COMPUTER STICK:  A dongle device from Intel, Asus, Lenovo and others that plugs into the HDMI port on a TV, turning it into a computer.  About $125.  See also, stick computer.

COMPUTER WATCHES:  See, Metawatch, Apple Watch.

CONCATENATION:  One of those fancy words that sounds complicated, but is really quite simple: A term applied often to computer programming (e.g. in encryption algorithms, see below) which refers to the operation which joins two character strings end-to-end.

In English, think:  foot + ball, when concatenated, equals “football”.  For audio, consider the “talking clocks” which actually string together (i.e. “concatenate”) a series of discreet recordings, as in “at the tone” + “the time will be” + “eight” + “thirty five” + “pm”. 

For computers, in the much more complicated area of encryption, a randomly generated IV (“Initialization Vector”) is added to (i.e. concatenated) the generated number of bits in the algorithm to create the complete RC4 encryption key.  The IV is therefore concatenated with the bit key already generated.  Example:

{a69UuwhE34HutilMN392gipla} {shjkUPU329sn90}

 64-bit encryption key              +   24-bit IV             

= Complete RC4 (concatenated) 64-bit Key: a69UuwhE34HutilMN392giplashjkUPU329sn90             

CONDUIT:  An enclosure to carry wire(s) or cable(s), usually made of PVC or metal.  See Raceway.

cable vs wire

CONFICKER (a/k/a/ Downup, Downadup or Kido):  A worm virus targeting Windows computers, first detected in 2008, and which is very difficult to remove because of its rootkit nature.  It is now believed to be the largest computer work infection since the 2003 SQL Slammer virus. See, Spyware.

CONNECTIVITY: The ability of a computer to connect to other computers, whether in a closed network or, most commonly, to the InternetWhen we ask if the computer has connectivity, we’re usually asking whether it’s connected to the Internet.

CONSENSUAL BUGGING: The intrusion and tracking you expressly agree to through FaceBook (which can track you even after you’re logged off), Blippy, Foursquare, Footpath and their ilk.  And also your cell phone’s search, voice search and Siri features and geo-location services.  You know about these.

CONSUMERIZATION: The migration of consumer products into the workplace (enterprise), such as iPad and smart phone users who bring their devices to work to connect to their email and other services.

CONSUMER ELECTRONICS SHOW (See “CESabove): An annual trade show hosted by the Consumer Electronics Assn. (see Associations) starting in 1967 to promote the growing demand for consumer-size products from electronics manufacturers.    Both were founded by Jack Wayman, who died on August 30, 2014 at the age of 92. 

CONTACT SCRAPING:  The practice of obtaining e-mail addresses from web sites, customers and other sources for marketing purposes.  Often, this is done using Programs (such as Outwit,, and that misleadingly represent themselves as list-builders for site owners and e-mail marketers, but which are actually used for illegitimate purposes as well.  Also included in this definition is the way certain social networking sites such as FaceBook, LinkedIn, ShareThis and Plaxo, by prompting you to build your “friends” list by importing your contacts or webmail lists, can then “scrape” your addresses for marketing. See consensual bugging, content scraping.

CONTAINER:  Used almost exclusively in enterprises, containers are essentially an entire runtime environment (i.e. an application as well as all of its “dependencies,” like libraries, binaries and configuration files to run it) in a single package (“box”).  Similar to virtual machines, but generally much smaller in size, partly because while VM machines must include an entire operating system plus the application, containers share the existing O/S kernel with other containers and apps, thus drawing far fewer resources. This lets developers move applications between different computing environments and from testing to staging to production and deployment, or from a physical machine to the cloud in a prompt and reliable fashion.  First offered with Docker’s Swarm, Apache’s Mesos, CoreOS and Kubernetes (the Linux open source container which seems to be heading for the default) it requires that the underlying host O/S run a container interface and hosting engine.  After that, you can run any software in a container without going through the usual installation process, vastly increasing agility across the enterprise.

CONTENT FARM:  A web developer which churns out hundreds of articles, many of which are mindless or useless, but based on what people are searching for on the Internet, in order to increase rankings on Internet search engines.

CONTENT SCRAPING:  The practice of illegally copying original (often copyrighted) content from one web site to another without the owner’s knowledge or permission.  It happens all the time, hard as you may try not to.  [If you look through this site, for example, I’ve done my best to credit others for the few things I didn’t actually write, through credits or links.]  But there are many cases of gross copying, mainly to steal high-quality, keyword-dense content to drive business to the stealing website.  See also, Contact Scraping.

CONTEXT MENU:  The drop-down menu that appears when you right-click on an icon, providing choices like “Open With...”

CONTEXTUAL TAB:  A feature of the Microsoft ribbon interface on menus that displays commands only when you need them with relation to a specific object.  For example, selecting the drive tab will show a tab for formatting, cleaning and optimizing drives; selecting an image tab will display commands like rotate and set as background.

CONTRIBUTION MODEL:  A purchase payment method, most often used in Internet subscriptions, where the user is allowed to pay whatever it’s worth to them for the service.  Of course, they may be offered incentives to pay more at various threshold levels, but they don’t have to do so in order to remain subscribed.

CTRL keyCTRL (“Control”) KEY:  A key on the standard computer keyboard which serves essentially the same function as the Apple’sCommand” key, that is a shortcut to various menu options when it is depressed and held along with another key.  The CTRL key sequences date back to teletype systems, where certain commands were mapped into the ASCII character set.  The ASCII set, which was created in part to standardize the communications protocols between teletype machines (which had just replaced the telegraph) sent commands to control certain non-printing functions such as the movement of the printing cartridge. Hence the name “control,” as the sequence actually applied a sort of offset to the ASCII code, sending a different signal which would produce an effect not related to the actual typing. Because Apple computers running OS X are based on Unix, and the Terminal application found in Unix utilities could reasonably considered a software version of the old teletype system, it makes sense that the CTRL key would be used to send commands to the computer to be executed.  In the case of PCs, most of the original keyboards were left over from terminal-based systems also with roots in teletype systems, so it was natural that Microsoft would use the leftover key to map menu actions and keyboard shortcuts without having to add an extra key as Apple did.  Of course, now Windows gives users the ability to individually map keyboard keys as they see fit if they so desire.

CONTROLLER:  A  part of a computer, typically a separate electronic circuit board or chip, either on the motherboard or in a plug-in card, which allows the computer to run certain kinds of (peripheral) devices, such as hard drive(s), floppy drive(s), keyboards and graphics.  See, e.g. PCI. And microcontroller, which has only a single integrated circuit.

CONVERGENCE:  This is a buzz-word created in the 1990s often used to define a situation in which different hardware devices are combined to provide similar functions to the end user.  For example, both cable (e.g. Comcast Xfinity) and DSL (e.g. Verizon) provide combination hardware boxes which split the signal into telephone, internet and television segments, providing the end user with all three services from the same provider.  Similarly, the smart phones provide convergence of e-mail, web browsing, games, GPS, phone and other services, all on the same device.  Apple, too, has embraced this concept (in its own way).  Starting with iPhone 6 and iOS8, it has embedded a feature called “Continuity,” which let users start an e-mail or other task on their Mac, pick it up on their iPhone and then move it to their iPad or even their Apple watch.

There are additional specialized types of convergence:  Technological convergence, digital convergence, network convergence all have a similar meaning - the tendency for those technological systems to evolve toward performing similar tasks.  For example, digital convergence interlinks previously separate technologies like voice, telephone, data and video resources so that they interact with each other in a synergistic manner.  Generally, linking computers with telephone or video or data.  Hyperconvergence involves such products as Cisco’s UCS, IBM’s PureSystems, Scale’s HC3, and VCE Block, all of which not only extend the convergence trend into a smaller form factor, but also bring the use of hypervisor (hence the “hyper”) virtualization, which melds the virtual and physical aspects of infrastructure together, resulting in a single solution running all applications, including servers, storage and computers. 

CONVERGED NETWORK FABRIC:  Refers to the merging of both SAN and LAN into a single network fabric.  This is fairly complicated stuff, used mostly in very large organizations (“enterprises”).

CONVERGED INFRASTRUCTURE (“CI”):   Also sometimes referred to as “unified computing,” “datacenter-in-a-box” or “infrastructure-in-a-boxAn approach to data center management that relies on a specific vendor and possibly its partners as well to provide a pre-configured bundle of hardware and software which can be centrally managed.  CI minimizes compatibility issues, simplifies management and can reduce cabling, cooling and power costs.  Additional bundled services may be virtualization, cloud bursting or disaster recovery, providing administrators with the ability to completely manage both physical and virtual infrastructures in a federated manner.

COOKIEA cookie is basically a piece of information sent to a web browser by a web server.  This is how some web pages “remember” your previous visits.  Cookies normally store very basic information such as your IP address or preference or log-in information (in an encrypted form).  They do not provide any private information, nor are they inherently bad, although they can be abused through the use of malicious software (see the SPYWARE page for further information).  If you’re still confused and don’t quite understand the difference between good and bad cookies, click HEREIncidentally, The name “cookie” is derived from UNIX programming objects called “magic cookies,” which are tokens (a single element in a programming language) that are attached to a user or program and which change according to the areas entered by that user or program.

icicles COOLING:  Probably the single most damaging threat to computers is overheating.  Over the years, there have been many ways to eliminate this waste heat from computer components, including fans, heat sinks, liquid, super-cooled gasses, etc.  The most common cooling on today’s computers is provided by fans and heat sinks.  For more, see heat sinks.  Also, there is an animated graphic and excellent detailed discussion about virtually every possible type of cooling on Wikipedia under “Computer Cooling”.

COOPER, MARTIN:  The man who invented the first cellmartin cooper phone (for more, see cell phone definition, above) and made what is widely considered the first cell phone call from a sidewalk on Sixth Avenue in New York City, using a Motorola DynaTAK 8000X on April 3, 1973.


COPROCESSOR*A special set of circuits which is dedicated to a specific function (usually manipulating numbers) faster than the basic microprocessor chip can do so, while taking some of the burden off the microprocessor.  Older computers used to have a separate chip on the motherboard for this purpose but, starting with the Intel Pentium chips, it was merged into the microprocessor and called the math or numeric coprocessor (see ALU) or sometimes the “floating point chip”. 

COPY/CUT and PASTE:  One of the great advantages in word processing, the ability to move and/or reuse text throughout and between documents.  Reportedly pioneered by computer scientist Larry Tesler (and Tim Mott), who first added this software function to Gypsy WP in 1974 while at Xerox/PARC.  Tesler was also in charge of the Newton pad while at Apple.

COPYPASTA:  A block of English Internet text which has been repeatedly copied and pasted repeatedly over the InternetIt’s not named after pasta because it can be a sticky mess, but rather is a portmanteau of “copy and paste,” probably coined by 4can’s Anon Dramatica around 2006. See creepypasta, below.

CORE*One or more central processing units residing on a computer’s CPU, as in one of the Intel or AMD processors.  Newer PC processors now commonly have dual-core or quad-core chips, which have two or four cores on a single processor chip.  (AMD is talking about manufacturing a 12 Core chip soon!) This is done to increase clock speed and therefore performance without generating much more heat or using much more energy, and is particularly well-suited for multitasking environments and servers.  On the R&D side, MIT is testing an experimental 36-core chip for research.

CORE DUMP:  The file created when a program crashes and the contents of the memory used by that program are saved to your hard drive.  This file is then used to analyze the reasons for the program crash.

CORNER CASE:  See edge case.

COROLET:  The name of an experimental computer operating system from IBM, which varies from sequential architecture like the Van Neumann paradigm, and is based on neural networking and AI and intended to be used with upcoming IBM neuromorphic processor chips.  Corolets are like programs which control specific individual functions and can be linked together to build a more complex operating system structure, much like the human brain functions.

CORRUPT:  Computerspeak for “damaged”Data files, programs and operating systems can become corrupt.  Some, but not all, corruptions can be repaired.  For electrical corruption, see Dirt.

CortanaCORTANA:  Microsoft’s personal digital assistant, Jen_Taylorjust like Siri for iPhone and Google Now for Android.  Introduced in beta as part of Windows Phone 8.1 in mid-2014, Cortana accepts commands to  surf the web, make your appointments, tell you the weather and the like, replacing the built-in search function on the Windows Phone. Her name comes from a popular AI character from Microsoft’s Halo video game.  The voice in the games, the app and movies like “The Cortana Chronicles: In Search of Fandom,”  and in games like The Matrix, Super Mario and Everquest are all played by Jenn Taylor, an American voice actress.  In 2016, keeping up with the heated competition from Siri and others, Microsoft acquired AI company Genee, an AI scheduling service. See Digital Assistant, FAQ 92.

COS:  Class of Service, meaning that internet traffic can be categories into different priorities.  See QOS tagging.

COSMIC AC:  The universe-spanning computer in Isaac Asimov’s short story, “The Last Question”.  This computer could answer any question it was asked, as it contained all knowledge in the universe.  It made HAL, the computer in 2001, look underpowered.  See this LINK for the story of this all-knowing, hyperspace-dwelling computer.

COSPLAY:  “Costume Play”.  Dressing up and pretending to be a fictional (comic book, sci-fi, anime, etc) characters.  One sub-culture of cosplay would be the “Furries,” who have their own convention, where people dress up as furry animals (sorry, no real fur allowed.) See Comic Con, Fanboy, Geeks.

CPE:  Customers Premises Equipment.  See 66 Block.  A telephone term distinguishing the customer’s equipment from that of the telco.

CP/M:  Abbreviation for Control Program for Microcomputers.  Just like there was BetaMax before VHS became the standard, and HD-DVD before BlueRay, there was CP/M before DOS became the standard.  According to Webopedia, CP/M, created by Digital Research Corp. (“DEC”), was one of the first 8-bit OSs for personal computers.  However, DEC made a critical strategic error by not agreeing to produce an operating system for the first IBM PC.  According to folklore, DEC’s president was flying his airplane when IBM came to call.  (See DOS for more history.) When he missed the appointment, IBM marched out and never looked back.  Instead, IBM turned to Microsoft Corp., which developed MS-DOS, based on version 2.2 of CP/M.  By the mid-1980s, MS-DOS had become the standard OS for IBM PCs, and CP/M was obsolete.

CPM:  Cost Per Thousand.  A common metric for web site publishing.  A publisher might charge $4 CPM, meaning that the advertiser must pay $4 for every thousand impressions of its ad.  the “M,” of course is the roman numeral for 1,000.

CPRM:  Stands for Content Protection for Recordable Media, the content protection used for the SD Memory Card, using “key revocation.”  This technology was developed by the 4C Entity for the purpose of providing a high level of protection against illegal copying of copyrighted music and video.

CPU*: This is the “Central Processing Unit”  (sometimes called the “system unit”) for your computer. Your ”computer” is actually the “box” that has the button that you use to turn the system on and off.  (On a desktop, it’s the large rectangular box that has the drives in it, on a laptop, it would be the part with the keyboard.)  Anything attached to the box is a “peripheral” such as the mouse, keyboard, monitor, scanner, printer or the like.  The CPU is the computer “chip,” or processor, inside the computer box.  It is a silicon wafer, about an inch and one half inch square and maybe an eighth of an inch thick, onto which is inscribed the “brain” of the computer.  Basically, it contains ALUs which fetch and decode hardware, instruction pipelines, interrupts and I/O control hardware.  In English:  It processes the operating system instructions driving the computer. CPU chips are manufactured by companies like Intel and AMD, and are made in varying speeds and numbers of cores, such as 2.4Ghz, 3.2Ghz, dual-core, quad-core, etc. For a complete listing of all of Intel’s chips, from the pioneering 4-bit 4004 in 1971 to the current quad-core 4 bit chips, click HERE; for AMD’s chips, click HERE.



The MOTHERBOARD is the actual circuitry that operates the computer. It’s a large (about 8” or 10” x 12”) printed circuit board.

There are fixed  (permanent) chips on the motherboard known as CHIPSETS that control certain functions, such as the amount of RAM and types and sizes of various (video, sound, ethernet) processors that may be attached to the board.

The brain of the computer is the PROCESSOR, sometimes called the CPU (“central processing unit”), a large removable chip that plugs into the motherboard and contains the logic circuitry that processes the operating system instructions driving the computer.  Usually the heat sink and fan sit atop it. The processor chip may have multiple internal CORES, each of which is an independent but interconnected central processing units, hence the terms “dual core” and “quad core”.

The CHIP embedded in the processor is the semiconductor  MICROPROCESSOR that is the “brain” of the CPU. Sometimes is is embedded with another circuit called a CO-PROCESSOR which is dedicated to performing specific functions such as mathematics.  Those functions not embedded within the processor are contained in the chipsets, discussed above.

For what makes a computer “faster” click HERE.

motherboard components.jpeg

CRACKER:  a/k/a White Hat.  A term created in the mid-1980s by HACKERS who wanted to differentiate themselves.  Crackers’ sole aim is to break into secure systems.  Hackers maintain that they only break into the systems in order to gain knowledge about them and, once in, sometimes engage in playful pranks, nothing more.  (The difference is sometimes difficult to ascertain.)  As a noun, the term CRACK is universally understood - it means to break (“crack” like a safe) various software registration, activation or copy protection devices in order to copy or use commercial software illegally, without compensation.  See WAREZ.

CRAM/CRAMMING:  (1) Challenge-Response Authentication Mechanism. A two-level scheme for authenticating network users that is used as part of the Web's Hypertext Transfer Protocol (HTTP). The two levels are basic authentication and digest authentication.  (2) Also a term describing those mysterious charges — for an assortment of memberships and services that have long been showing up on wire-line (“POTS”) telephone bills and lately on text and SMS statements. These charges are defined as cramming if they come from a third party and if consumers didn’t ask for them.  In May, 2015, Verizon and Sprint agreed to a $158 million settlement to pay subscribers for their part in text cramming their customers.

CRASH:  A condition where a program, or the entire operating system, stops performing its intended function and will not respond to system commands.  Most often, the entire computer “freezes” and must be rebooted.

CRAWLER:  See, Spider.

CRC:  See, checksum, above.

CREEPYPASTA:  Short stories (and sometimes blogs) posted on the Internet with the specific intent to shock, unnerve and startle the reader.  Similar to “urban legends,” but not always text - it can be images or videos as well.  Derived from the internet slang “copypasta,” which refers to text that has been repeatedly copied and pasted by users again and again, often gaining some apparent truthfulness as it repeats itself, only it applies to whole stories.  See, e.g. Slenderman.  Also Jeff the Killer, Smile.jpg and Squidward’s suicide.  Updates include stories with video narration, like Ben Drowned, Polybius, Snuff Film, etc.  See the Creepypasta Wiki for examples and current trends and the explanation by the members that they are normal people who simply like scary stories and not horrible people who condone actions like the Slenderman case.

Michael CronanCRONAN, MICHAEL:  A San Francisco based graphic designer and marketing designer of the firm bearing his name, famous for developing the brand names Kindle (he likened the use of the new e-reader to “starting a fire”) and TiVo (keeping the familiar TV in name and logo and using “vo” for vocal sound and voice) and their logos.  He died in January, 2013. 

CROSS-PLATFORM: This is a term which refers to computer software or hardware which can be used on different platforms (i.e. computers and other devices with installed operating systems, like PCs, Apple, Linux, etc.).  An example of cross-platform software would be a web browser.  Closely related is WORA software (“Write Once, Run Anywhere), primarily used with phone and pad apps, so that they will be compatible with Apple, Android and other O/S platforms.  It’s still not perfected, sometimes dubbed “Write Once, Debug Everywhere”.

CROSSTALK:  Unwanted interference on a communication circuit (e.g. telephone or computer) caused by the transference of energy from another circuit as between untwisted wires inside a cable or between two devices (e.g. wireless phone and TV remote).

CROWD-:  As a prefix, it generally denotes an Internet based group, as for funding or information sharing, as defined below...

CROWDFUNDING:  Asking a crowd of people (usually through an Internet site like, which is the most popular microfinance site) to donate a defined amount of money for a specific cause or project in exchange for various rewards.  There are three general types:  Equity-based, Donation-based and Debt-based. Some refine the types - Take Bleep, a smartphone cable that comes with an app to back up your data while charging the phone.  It’s Israeli developers have a crowdfunding page which solicits donations in return for which donors receive the USB cable which can be used when development is complete and others will have to pay for the entire kit.  Popular crowdfunding sites: Patreon (artists), Crowdtilt (raising money for group objectives),  Razoo (raising money for causes), Credibles (small food businesses), Petridish (science discoveries), Crowdfunder (investment and equity funding), Crowdrise (fundraising), GoFundMe (personal fundraising) and (more fundraising). Kiva also developed Kiva Labs, which attempts to reach people who have been left out because they live in rural areas, like farmers and students.

CROWDSOURCING:  Teams of people, interacting over the Internet, applying their knowledge and abilities to solve complex scientific and business challenges.  The original term was coined by Jeff Howe and Mark Robinson, editors at Wired magazine in 2005, and was a portmanteau  for the comparison to “outsourcing to the crowd”.  Over time, its meaning has been expanded to include virtually every type of cloud collaboration, including business, funding, development or solving any problem and then sharing the answer with others.  An example would be the contest by Netflix, the movie rental company, challenging software writers to develop recommendation software more accurately predicting the movies that its customers would like to rent.  A prize of $1 million was offered.  (The contest was won in October, 2009 by a collaboration of statisticians, machine-learning experts and computer engineers from the U.S., Austria, Canada and Israel calling itself “BellKor’s Pragmatic Chaos”.)

CRM:  Customer Relationship Management”.  This is an overall business strategy built around the idea of being “customer centric”.  CRM fosters an understanding of the customer based not only on demographics and purchasing patterns, but also their empowerment at touch points, i.e. web interaction, employee contact, telephone service, etc.

CRUD:  See, Database.

CRYPTANALYSIS:  The study of secret code systems, including encryption, that is intended to lead to finding weaknesses in them so that the code can be broken and thus permit the retrieval of the plaintext from the ciphertext without determining the key or algorithm.

CRYPTO:  A prefix to indicate that what follows involves the encryption, or hiding, of data or other things (like people, if you’re a cryptoanarchist).

CRYPTOGRAPHY:  The science of information security, derived from the Greek word cryptos, meaning ”hidden”.  It means encoding data so that it can only be decoded by specific individuals having the appropriate tools.  Usually involves creating “cyphertext” through an algorithm combining the original data “plaintext” with one or more keys (“ciphers”) which are numbers or strings of characters known only to the sender and recipient.  See, encryption.

CRYPTOANARCHIST:  A person who uses technology and the free market to protect privacy as a means to assert autonomy from the government, creating a society that is often hidden, decentralized and separate from political power.  An example would be the creation and posting of a 3D printed handgun by Cody R. Wilson, making it available to all citizens without government regulation.

CRT:  Cathode Ray Tube - most older monitors, the ones that look like (the older) TVs. See, screens.

CSMA/CD:  The technique used to control the flow of information over ethernet cables across a network.  This is an acronym for “Carrier Sense Multiple Access with Collision Detection.”  Carrier sense means that a computer listens to a cable before sending a message to assure that no one else is sending a message right them.  Multiple access means that there is nothing wrong with two (or more) computers sending messages across the cable at the same time, so long as they alternate their packets.  Collision detection means that the computer listens to see whether it’s transmission got through or whether it may have collided with another message, in which case it re-sends the message.

CSRF:  Pronounced “sea surf”.  Cross-Site Request Forgery.  Also referred to as “session riding”, “One Click Attack”, or “XSRF”.  CSRF attacks use security flaws in cookies, password requests and other interactive Web components to intercept communications between your browser and a Web site’s server.  Even encryption won’t protect you.  In April, 2009 G-mail experienced CSRF attacks.  See also, XSS exploits. For more, see SPYWARE.

CSS:  Content Scrambling System.  A method of recording commercial DVDs so that they cannot be copied.  ALSO: Cascading Style Sheets, which is a method of creating web pages with uniform layout elements such as headers, fonts, borders, color, etc. for each web page in a site.

CSU:  Channel Service Unit.  See DEMARC.

CTRL+ALT+DELETE:    See Three Finger Salute.

CURATION:  Sometimes, Editorial or Media Curation(1) Curation is part of the integration of Internet media content (usually for news and other digital magazines) using both machine as well as human resources.  It is an important part of the process of aggregation (gathering the content from sources on the Internet), curation (sorting and categorizing it), and then presentation to online users through blogs, magazines, posts and the like.  (2) This term also applies to curated “boxes,” those “specially selected” sample (promotional) items, usually by genre (e.g. cosmetics, toys) delivered to users’ doors by schedule after signing up on the web.

CurrentC logoCurrentC:  The retail industry’s answer to Apple Pay and the other digital wallets.  The mobile payment system will be used by WalMart, Target and Best Buy when it is launched as a trial program in August, 2015.  The CurrentC agreement will not allow those chains to accept other mobile payment plans.

CURSOR:  A movable spot on a visual display, showing the user the point (or sometimes the range) at which commands such as typing may be applied. The cursor may be controlled by the mouse or directional arrow keys, or both. The cursor may change form in order to meet its function, e.g. from an “arrow” for an insertion point, to a “bar” for text commands.

cutting the cord royalty free“CUT THE CORD”:  A phrase used to describe the use of Smart and Internet TVs to circumvent the use of cable and satellite connections for their TVs, reducing the subscription costs.  See FAQs 44 and 46 for a full explanation.

CUTTING EDGE:  Just like the edge of a knife is the cutting edge, a technology or company on the cutting edge is in the leading or forefront of the field.  See also, bleeding edge, ascendant.

CVV:  The “Card Verification Number” on the back of your credit card.  Also known as CSC (“Card Security Code”) or CVV2 (second generation CVV), its purpose is to prove to an online merchant that you physically have the credit card.  It’s three digits long (on Visa, MasterCard and Discover) and four digits on Amex cards. It is NOT your PIN, which is secret and is used at an ATM or sometimes when making in-person purchases with the card.

CXO:  Chief Experience Officer, a/k/a Chief Client Officer, Chief Customer Officer.  Another example of the tech “title inflation” in the 2000s.  In an enterprise organization, the officer responsible for the overall user experience (“UX”) of that organization.  The CXO may design and implement the user interface, handle marketing and relations between the enterprise and consumers, the community, the investors, even within the organization.

CYBER:  As in “cyberspace.”  Refers to a type of relationship which is on-line or only through the use of the Internet.  The prefix can be attached to virtually anything, e.g. Cybermom - a mother who’s constantly connected to the Internet.  More common cybersuffixes (!) are discussed below...

Cybercommand logoCYBERCOM:  Short for USCybercom, the United States Cyber Command, headquartered in Ft. Mead, Md.  This is the “fifth domain” of military operations (after land, sea, air and space) and the first man-made domain.  The Pentagon command, which was created by President Obama in 2009, became operational in October, 2010 and is charged with defending the country against real-world enemies in cyberspace.  As the NSA’s presentations claim, “The next major conflict will start in cyberspace”.   CYBERCOM is also is a major focal point in active preparation for America’s digital wars of the future as well (see LINK), for example through the Polterain project, operated by the NSA’s Tailored Access Operations (“TAO”) department, responsible for breaking into computers.  Surveillance is only “phase 0” in the U.S. digital war strategy.  In 2011, Pres. Obama signed executive orders giving the military the all-clear to use weapons that can perform tasks ranging from espionage to the crippling of an enemy’s electrical grid (The latter would, however, require a Presidential directive).  [Bloomberg Businessweek, 7/25/11, p. 57]  This is a recognition that, in preparation for the wars of the future, the so-called “ABC Weapons” (atomic, biological and chemical) have been updated to include “D” (digital) weapons as well.  This, in addition to civilian agencies such as Homeland Security, the CIA, the NSA (which is really military) and the FBI, which have their own programs.  The Center for Information Dominance (“CID”) at the Navy’s Corry Station Base in Pensacola, FL houses the Pentagon’s primary training facility in the art of cyberwar.  In order to do this, the Command arguably monitors and controls to a degree all of the activity on the Internet.  While the U.S. Army, Navy, Marines and Air Force already have established their own cyber forces, it Admiral Michael Rogersis the NSA (also officially a military agency) that is taking the lead.  It is no coincidence that the director of the NSA also serves as the head of CYBERCOM.  The country’s leading data spy, Admiral Michael Rogers is also its chief cyberwarrier and his close to 40,000 employees are rNSA sign2esponsible for both digital spying and destructive network attacks.  (Incidentally, as expected for a security agency, the 32 numbers in the inner gold circle around the eagle on the logo form a secret code which, when run through an md5 cryptographic hash, reveals the command’s mission statement.)  See also, How the NSA Does It, Privacy, Are You Being Watched.  For the relationship between these agencies, note that the building sign includes all three (see photo at left).

Related to protecting the public from cybercrime on the civilian side of the federal government are the National Counterterrorism Center (created after 9/11 to coordinate sharing of intelligence within the federal government) and the Cyber Threat Intelligence Integration Center (“CTIIC”; created in 2015 to monitor cyber security threats and share data about possible attacks among federal government departments and the private sector).

Space_Command1Also closely related is the U.S. Air Force Space Command (a subordinate command to U,S, Strategic Command) at Peterson AFB, Colorado, started in September, 1982 to provide the U.S. with anti-satellite protection and possibly warfare capabilities.  It operates some 30 satellites in space, many of them providing free GPS, both military (directing smart bombs against ISIS) and civilian (providing turn-by-turn navigation for smart phones).

CYBERCRIME:  Crime perpetrated over the Internet.

On Line ShoppingCYBER MONDAY:  Refers to the Monday after “Black Friday,” the Friday the day after Thanksgiving, on which brick-and-mortar stores claim to give their greatest discounts to increase their profits on the day they’re supposed to go “into the black” for the yearSimilarly on Cyber Monday, the Internet stores offer their greatest Christmas shopping discounts to encourage on-line spending for the holiday.  Check with, for example, for information about discounts.  The National Retail Federation claims to have coined the term in 2005 to promote shopping, of course.

CYBERNETICS:  See, cyberpunk, below.

CYBERPUNK:  See cyberspace, below.  A science-fiction genre which is a contraction of the words “cybernetics” (the study of  communication, control and feedback in machines and living systems, as coined by math prodigy Norbert Weiner, its originator) and “punk” (a young person, especially a member of a rebellious counterculture group).  It features descriptions of advanced science coupled with a radical change in social order, populated by classic loners, often young hackers, who fight the system.  Think movies like “The Matrix” and “Blade Runner” and many video games.  See also steampunk.

CYBERSPACE:  A term coined by author William Gibson in his 1984 novel Neuromancer (the first installment of The Sprawl Trilogy), which represents the totality of all connected computer networks and their contents in a future world.  The term is now currently used as generic slang for the Internet and all of the information in it.  The novel is often cited as an example of cyberpunk (see above), a science fiction genre which uses exceeding detail, carefully constructed intricacy, and techniques redefining the nature of humanity. 

The defining difference between cyberspace and physical space is that cyberspace is a manmade landscape of interconnected devices and networks. which are organized and managed by private and cooperative organizations without state or geographic overlap.  Because of this lack of governance and central control, it is exposed to a wide variety of threats, such as cyberwarfare, intrusions and viruses.  The rapid pace of changes in the internet structure make it hard to maintain continuous vigilance.  Further, the structure of the TCP/IP protocol makes it difficult to identify the source of an attack and the declining cost of perpetrating an attack is making the software for doing so readily available to almost anyone.  Whether you are a business or the government itself, a strong defense is essential.  For more, see the (“Talinn”)  Manual on International Law of Cyberwarfare in LAWS.

CYBERSURVEILLANCE:  Shorthand for the U.S. Government’s unauthorized spying on U.S. Citizens using things like the NSA PRISM program and other software through the Internet. See LAWS.

CYBERWAR:  Attacks waged by so-called cyberterrorists who attack computers, networks and systems with intrusions, viruses, malware and spyware on a large scale (e.g. DDOS attacks) and particularly against government computers and the Internet itself.  See, Cyberspace, above.

CYBERTERRORISTS:  The use of the Internet to effect terrorist attacks, such as disruption of computer networks, propagation of computer viruses, denial of service attacks and the like.  This is an evolving definition.  For more on this subject, see the discussion of the Tallinn Manual under LAWS.

CyrixCYRIX:  A computer processor chip manufactured by Cyrix Corporation (Richardson, Texas) founded by Jerry Rogers and Tom Brightman in 1988 which developed upgrade and overclocked chips for PCs which were a popular and cost-effective alternative to Intel and AMD chips in the 1990s.  Many computer builders used the Cyrix chip to improve the performance of 386 boards into budget 486 boards by upgrading the chip.  The company merged with National Semiconductor in 1997 and chips are no longer manufactured under the Cyrix name.  Personally, I always found them to be buggy and defective (peripherals didn’t work right, installs were often incomplete, etc.) and I believe that’s one reason NS didn’t push the brand.