“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.


PaaS:  “Platform as a Service” is an outgrowth of the Software as a Service (“SaaS”) application delivery model.  The PaaS model makes all of the facilities required to support end-to-end life cycle of building and delivering web applications and services entirely available from the Internet with no software downloads or installation.  Also known as “cloudware,” PaaS includes workflow facilities for application design, development, testing, deployment and hosting.

PACKET: a/k/a “datagram”. A single unit of binary data which is routed across a computer network, including those connected over the internet. For speed and reliability, data sent between the networked computers is divided into packets rather than lumped into one large transmission.  Packets are formatted for different protocols, but each generally includes a header [which lists the destination IP address], the body (a/k/a “payload”) which contains the message data and the footer (sometimes called the “trailer”), which ends the message, often with a “magic number” which checks to insure that the entire message has been received.  The receiving computer reassembles the packets in the correct order, checks for full transmission, applies encryption keys where required and delivers the data.

PACKET SWITCHING:  See, Internet.   Along with TCP/IP (the language which effectively “links” the computers on the Internet, packet switching technology, which breaks up files into smaller packets (no larger than 1500 bytes) for transmission over the Internet and then reassembles them back again at the destination, were the two major inventions that propelled the Internet. See Paul Baran, early inventor of packet switching.

PACKAGES:  Libraries of software that can do specific tasks, like reading files, communicating with web ordering services, or the like, on the web, often using JavaScript.  There are millions of packages available, for every imaginable purpose.  Software packages are installed using the NPM (“Node Package Manager”).

PADDING:  In word processing, the amount of space surrounding the text in a text box, separating it from the border, often measured in pixels.

PAE:  Physical Address Extension.  If your version of Windows supports DEP, you may be able to use PAE technology to increase the hardware limit of 4Gb of RAM by adding additional address extensions.  Not always, though.

PAGEJACKING:  Seejacking.”

PAGE FILE (a/k/a VIRTUAL MEMORY):  Sometimes, depending upon the Operating System, also called the Swap File or Partition. This is a reserved portion of the hard disk drive that is used as an extension of RAM for non-critical data in RAM that hasn’t been used recently.  Since a page file can be read from the hard disk as one contiguous chunk of data, it’s much faster than re-reading data from many different original locations.  In order to maximize (increase the speed of) the system, administrators and techs often reset that optimal size of the page file.  See Virtual Memory.

PAGE RANK:  Generically, a measure of the popularity of a web page on the Internet, used in web site optimization.  Specifically, PageRank is a patented Google link analysis program named after Google founder Larry Page, which assigns a numerical rating to each page measuring its relative importance on the web.

PAIRING:  Actually, “Trusted Pairing”: The process of connecting Bluetooth wireless devices such cell phones, headsets, earbuds, etc. which, when “discovered” by each other, establish a “trusted paired” connection using an assigned passkey (usually “0000”).

Palinter logoPALINTIR:  Pronounced “palanteer”. A computer services company located in Palo Alto, CA which specializes in data analysis.  It was founded in 2003 by Peter Theil, funded in part by In-Q-Tel (the CIA’s investment arm), and primarily serves the U.S. government like the DoD and Intelligence Community (through Palantir Gotham [formerly Palinter Government]) and large companies (mostly financial).  The name comes from the “seeing stones” in the Lord of the Rings epic.  Because of its ability to accumulate data from millions of devices daily, then use quants, big data and AI analysis to determine and display interrelationships in an ontological fashion, it commonly used in law enforcement and terrorism circles.  For example, the LAPD uses Palinter to accumulate data through the light bars on police cars to scan thousands of license plates an hour, then cross-check registration records for telephones registered to the owners, property held by them and other indicia like credit card receipts, all connected to GPS indicators to determine patterns and physical locations for “predictive analysis” purposes.  The ACLU has objected to this as an invasion of citizen’s privacy, while the Government claims that, if you’re public, you’re fair game.

Palm logoPALM: One of the original popular manufacturers of personal digital assistants (“PDAs”).  The Palm Pilot was a major player in its day, before smart phones took the place of PDAs.  The company was acquired and put down by HP in 2010.

PAN: (1) Personal Area Network.  See Bluetooth for more. (2) Also, Primary Account Number, the primary credit card that you enter in your iTunes or Amazon account for purchases.

PANTONE:  Refers to a the most widely used color system of over 1200 standard colors developed by Pantone, Inc. in 1963 by Lawrence Herbert, Pantone’s founder.  Each color is specified by a number, and colors can be further broken down into a color calibration used by professional PANTONE LOGOprinters to calibrate color reproduction.  Solid colors generally have three digits, others four.   By permitting the specification of a color by number, you are assured getting the correct color when the file is printed, even though it may not look perfect when shown on your monitor or printed on every printer. Pantone Matching System (“PMS”) is used for “spot” colors (e.g., the background orange for this web page is identified as #6600); generally “process” colors are specified using the CMYK color model.  Spot refers to printing each color with its own ink; in contrast, process color printing uses four inks (Cyan, Magenta, Yellow & Black - CMYK) to produce all colors.  Spot color printing is effective only when the printed matter contains less than  three different colors, but becomes prohibitively expensive for more.  Click HERE for more.  For 16 years, Pantone has selected the “color of the year”.  For it’s 16th year (2016), for the first time it was two colors, Rose Quartz 13-1520 (pale pink) and Serenety 15-3919 (hues of lilac and blue-grey).

PAP:  Click HERE.

PARADIGM:  While this word has connotations outside of computers and engineering, at least since the 1960s the term refers to a “thought pattern” in a specific discipline, e.g. computer science, or programming. It is the set of practices that define a scientific discipline at any given period of time.  A major change in scientific thinking is often called a “paradigm shift.”

PARENT:  The directory one up from the one you are in, until you reach the topmost root directory for that drive.  See also child, root.

PARSE/PARSING:  The process of analyzing a string of symbols, numbers or text according to language or computer science.  Parsing can be “top down” or “bottom up” resulting in a hierarchal structure defining the data.

PATCH:  A program or piece of code that repairs a flaw, fixes an error or adds additional capability to a programMicrosoft issues groups of patches to its operating systems on Tuesdays, generally referred to as “Patch Tuesdays”.

PAYLOAD:  The “delivery” of a virus or malware following the intrusion into a computer.  See Spyware.

PERSONAL AREA NETWORK (“PAN”):  A computer network (also sometimes called a “piconet” of up to 8 active (and many more inactive) devices in a master-slave relationship (the first device being the master), used for communication among computer devices, including telephones, earbuds, radios, PDAs, Blackberrys, laptops, etc.  within a range of about 8 to 10 meters.  PANs can be used for communication between the devices themselves (intrapersonally) or for an uplink to the Internet.  A Wireless Personal Area Network is called a “WPAN”. Uses Bluetooth and other protocols.

PARALLEL:  A type of port and cables for those ports invented in the 1970s (See, Centronics), adapted for the IBM PC in 1981 and standardized by the IEEE in 1984.  It was primarily used for printers, but has been almost completely replaced by USB serial ports which are considerably faster.  Parallel ports are now hardly ever included on system boards.  See IDE for more discussion about parallel cables and connectors.

PARALLEL COMPUTING:  Solving a problem using multiple computers simultaneously.  This term covers a wide variety of possible architectures, including symmetric multiprocessing (“SMP”), clusters of SMP systems, massively parallel processors (“MPPs”), grid computing, distributed computing, cluster computing and hypercubing (binary multiples of computers, i.e. 4, 8, 16, etc.).  One example of this type of computing would be the model used by SETI (“Search for ExtraTerrestrial Intelligence), which is a huge grid computing project on the Internet that takes advantage of unused processing time in users’ computers to analyze radio telescope data.

PARAMETER:  A term originating in mathematics, but now commonly used for lots of things.  Simply: A value with a set limit. For example, a budget may have a set of parameters, limiting the dollar amount for each section.  In computing, a parameter could be a file name, value, monetary amount, code or time limit or the like.  But the idea is the same - a program may time out if it does not process within x seconds.  That’s a program parameter.  In developing software, the developer is given a set of parameters (i.e. values and their limits or boundaries) which must be worked within. The commonly used “search parameter” is a set of boundaries limiting the extent of an Internet search by date, extent or other limit through a query.

PARENT-CHILD:  See Taxonomy.

PARETO PRINCIPLE:  Sometimes simply known as the 80-20 Rule, was named after Vilfredo Pareto, an Italian economist, who observed that 20% of Italy’s population received 80% of its income.  He went on to test this theory in numerous social sciences and engineering and found it to hold true.  Symantec claims that the principle is applicable for phishing and virus attacks as well.

PARC:  Short for Xerox’s Palo Alto Research Center, a major contributor to many computer hardware and software innovations. See Xerox for more.

PARITY:  A method of checking for the accuracy of data transmission (i.e. “error detection”).  Used for telephone modem transmission, RAM usage, etc.  The term refers to the use of a so-called parity bit which is added to every data unit (typically 7 or 8 bits).  The parity bit for each unit is set for either odd or even, so that when the number of bits received is unequal to the ones sent, the receiver knows that there is a transmission error.  As you can imagine, it is not foolproof, and it does not actually correct errors, as does ECC or EOS.

PARSE:  Just like parsing an English sentence means to break down the sentence into it’s component parts, parsing in computers means to analyze or separate code (e.g. input) into more easily processable components.  For example, “parsing” an e-mail header means to break it down into its elements, so that you can see each and every “hop” from its creation to its destination, identifying the names of the computers, their IP addresses and locations and the time spent on each leg of its journey..

PARTITION: A physical section of a hard disk drive.  There must be at least one partition and possibly more, the number limited by the computer’s operating system.  Each partition must be formatted (e.g. into FAT, FAT32, NTFS, Linux).  There are three types of partitions - Primary (bootable); extended and (within extended) logical. Partitioning refers to the practice of dividing the storage space on a hard disk drive into separate data areas known as partitions. Each partition functions as a separate disk drive containing, for example, a second operating system, system recovery software or separate data files.  This facilitates backup, creates a barrier against viruses which infect the operating system, and allows operating multiple systems.  Various programs are common for this purpose (e.g. Norton Utilities, Partition Magic, Easus Partition Master), but starting with Windows 7 and thereafter, the Windows O/S has built-in software in the Disk Management section that is relatively simple to use for most partitioning tasks. See HDDs  and MBR for more.  Note: Many drives have “hidden” partitions (particularly for Windows 10) which contain information that should never be deleted (i.e. boot files,  recovery, system restore points) and can only be viewed with specialized software like Easus Partition Master. Don’t be tempted to remove them to make space on your hard drive if you don’t know what you are doing!!

Pascal logoPASCAL:  An early 3GL programming language (designed primarily for instructional purposes around 1967-8 by Nicholas Wirth) which was very structured, and has pretty much been superceded by C++ and Java.   

PASSIVE: Relies on whatever current comes from the connecting cable to a device, as opposed to active, which uses outside current to power the device.



PATH:  A common computer term referring to the description of the location of a file within the directory heirarchy of the hard drive (e.g. folders, subfolders, sub-subfolders).  Thus, a document may have the path: “C:\User\Documents\websites\glossaryP”.  It’s imperative for you to know the path of a saved file because, without it, it cannot be easily retrieved. Also, sometimes, a reference in graphic design and desktop publishing programs to the line that may be drawn around a graphic, perhaps to select it for editing.

PATCH:  A remedy or repair to existing code (program), usually to fix an error or vulnerability to a virus or intrusion.  

PAYLOAD:  Malware or virus programs that wreak havoc on your computer, often delivered by e-mail or installations. See Spyware.

PAYPAL LOGO  PAYPAL:  A San Jose, CA company (founded in 1999 and acquired by eBay in 2002 for about $1.5 billion, then spun off in 2014 as a separate entity) which is a global e-commerce business for conducting payments and money transfers over the Internet for purchases, for which it charges a fee.  It is used by over half of the buyers on auction sites such as eBay and also for commercial vendors.  It was created by Peter Theil and Max Levchin and was originally named Confinity (primarily a system for processing Palm Pilot payments), which then merged with (a financial services company owned by Elon Musk) in March, 2000, just before being acquired by eBay two years later as a full service payment processing company.  Since then, Paypal has expanded in payment venues (it has its own “wallet” like Google and Apple), fraud detection and announced in June, 2013 that it is even working in partnership with SETI and the Space Tourism Society to launch inter-planetary payments, a system for buying things in space when the time comes.

PBX:  Stands for Private Branch exchange, a private telephone network used primarily in offices, which share a certain number of outside (public) lines for making telephone calls external to the PBX.  It’s like a mini-phone company on the premises.  Offices use this type of system because it is significantly less expensive than connecting external telephone lines to each telephone in the organization, and it takes only a couple of digits to communicate between telephones within the organization.  A variation of PBX called centrex uses all switching at the local telephone office rather than at the company’s premises. Becoming superseded by VoIP, mobile and Internet phone (see Lync).

P2P:  Stands for “Peer to Peer”, a type of network (see File Sharing) characterized by each computer (“node”) having equal capabilities (as opposed to client server networks (a/k/a “hub-and-spoke”)) on which the responsibilities all reside on the server).  An example of P2P architecture would be the internet file sharing such as Napster, LimeWire, Morpheus and BitTorrent (almost of all of which have been discontinued, although they have been replace by others). See warnings about P2P in the SECURITY page.  See also, Gnutella.

P3P: Browsers such as Internet Explorer purport to block third party cookies from sites that don’t post a particular type of policy statement called the Platform for Privacy Preferences (a/k/a “P3P”) which is a protocol allowing websites to declare their intended use of the information they collect.

PC:  Short for ”Personal Computer,” but usually referring only to DOS and Windows (Microsoft) based computers, as opposed to MACs (Apple O/S) based computers.  Originally this term distinguished between very large mainframes and desktop computers, but more recently distinguishes between O/Ss. The very first PC was said to be the Alto, developed at Xerox’s famed PARC (Palo Alto Research Center) (get it?) by Charles P. Thacker and his team.  This machine so impressed Apple’s Steve Jobs that he modeled the Macintosh computer on it.  In the 1980s, IBM introduced the PC & PC, Jr.  For more about the first computers, click HERE.  Definition of computer, click HERE.  Lately, there is a version of the PC known as the “mini PC’” that combines a very small footprint with full power.  Examples for Win 10 would be the Asus VivoMini VC56R, ECS Liva X2, Gigabyte Brix and InFocus Kangaroo Pro.  These aren’t the same as the mini-factor Raspberri Pi computers, which are smaller and have less power and features.

PCB:  Short for Printed Circuit Board.  A thin plate on which chips and other electronic components are placed, usually soldered.   Computers have such boards, sometimes called cards, riser boards or adapters.  Virtually all printed circuit boards are made of fiberglass (glass-epoxy) resin, which is naturally greenish or tan in tint, over which a copper film has been deposited, which has then been partly removed PCB by etching with either ferric chloride or sodium persulphate.  Why are PCBs mostly green?  Although other colors are available, it’s true that they’re usually green. The general consensus is that the color green actually comes from the soldering mask material which has traditionally been applied to the board after it has been “printed” (the copper coating over the entire board has been removed to create the “circuit lines” on the board) for the purpose of preventing any stray solder from bridging the board circuits and also preventing corrosion, scratching or damage while still remaining transparent.

PCI:  Stands for “Peripheral Component Interconnect”.  Also, “Practical Communications Interface”. This is the most common type of “slot” (receptacle) in a computer’s mother (main) printed circuit board into which other printed circuit boards (often called “riser” cards or “expansion” cards or “controllers”) are inserted.   PCI cards add specialized capability to the computer’s main board for operations such as sound, video and modems.  There are a number of size variations of PCI cards, including compact, mini, low-profile and X.  Other, less common, types of expansion slots and cards are ISA (“Industry Standard Architecture”), EISA (“Extended Industry Standard Architecture”), MCA (“Micro Channel Architecture”), AGP (“Accelerated Graphics Port”) and CNR (“Communication and Networking Riser”).  Click HERE for photos of common slots.

PCI DSS: Stands for “Payment Card Industry Data Security Standard.  This standard, which was created in 2004 jointly by Visa, MasterCard, Discover and Amex, is a widely accepted set of policies and procedures intended to optimize the security of credit, debit and cash card transactions and protect cardholders against misuse of their personal information.  The six “objectives” of the standards are (1) a secure network (e.g. firewalls, passwords), (2)  protection of customer data (e.g. encryption), (3) protection against hackers (e.g. anti-virus, anti-spyware), (4) restricted access to information (e.g. IDs, passwords), (5) system monitoring and testing, and (6) development and maintenance of a formal information security policy.  (Most recently updated to v3.0 by 12/14.) Starting October 2015, banks have mandated a changeover from the old scan strip cards to EMV cards with embedded computer chips for security.  For most businesses, if they don’t have a reader for this type of card, they may be liable for fraudulent purchases.  See EMV for more...

PCM: Stands for “Pulse Code Modulation” which is a technology whereby standard audio signals (which are represented by waveforms) are converted into digital audio signals (which are represented by 1’s and 0’s) with almost no compression.  The PCM signal is converted back to analog form for distribution back to the speakers.  PCM should not be confused with either Dolby Digital or Bitstream, both of which encode in a different matter and which are compressed.

PCMCIA: Stands for “Personal Computer Memory Card International Association.”  This is an organization that has developed a standard for small, credit-card sized devices, called PC Cards that provide memory, cable, telephone, wireless and other capabilities, mostly for laptops that have a special PCMCIA slot for inserting these cards.

PCoIP: A VMWare protocol which improves performance over low-bandwidth networks.

PDAPDA:  Personal Digital Assistant.  These devices, manufactured by Palm, Compaq, Apple, Microsoft and others are basically the size of a deck of cards and contained a calendar, word processor and other programs.  Early PDAs did not contain a cell phone feature, newer ones did.  While they were popular several years ago, PDAs have been almost completely overtaken by Blackberry phones, iPhones and other full-featured smart cell phones, which include these features.  See Palm.

PDF:  Short for “Portable Document Format”, developed by Adobe Systems, this format is used to capture items developed using a variety of desktop publishing programs, allowing them to appear on the recipient’s computer as they were intended.  Adobe Reader, a free application from Adobe, allows the viewing of the program.  The full (paid) program, Adobe Acrobat, allows for creating and editing files in PDF format.

PDMI: Portable Digital Media Interface.  A 30 pin connector used with many tablet computers. Not the same as Apple connector.  See, connector photos.

PDU: Power Distribution Unit.  Any device which provides electrical power to data center equipment such as servers, storage devices and networking components.  There are many kinds of PDUs, including Basic (simple), Dual Circuit Intelligent (creating redundancy), Metered (monitors the amperage so it is not exceeded), Switched (ability to manage the load through a network connection) and ATS (Auto Transfer Switch)(ability to monitor with redundancy).

P/E CYCLE: See Program/Erase Cycle, below.

PEBKAC: A (geek derogatory) term which means “Problem Exists Between Keyboard and Chair, i.e. User Error.  Techs may use this term between themselves in front of a client to communicate the problem, much like other people will speak another language.  Kind of like PICNIC (Problem In Chair Not In Computer) or ID-iot error.

PEER-TO-PEER: A type of computer network in which all computers are equal, because each computer can be both a server and a client, depending on whether it is sending or receiving information.  The largest peer-to-peer network is, of course, the Internet.  This is the most common type of network, and it differs from the hub-and-spoke type network commonly used in intranets (e.g. offices), where a server (host) computer communicates with relatively dumb workstations (spokes). See also, Networks, Host, P2P.

PELTIER:  A type of computer cooling developed in 1834 by Jean Peltier, who applied a voltage to a thermocouple to create a temperature differential between two sides, resulting in a “heat pump”.  This was considered the inverse of the “Seebeck effect,” discovered in 1821 by J. Seebeck, who discovered that two dissimilar metals, connected at two different junctions, will develop a micro-voltage if the two junctions are held at different temperatures, creating what is known as thermoelectric cooling (“TEC”).

PENTALOBE:  (sometimes also called Hexalobe)Pentalobe screws Characteristically, Apple isn’t just content to have operating systems, connectors and provisioning different from everyone else, but they have now invented the pentalobe (“5-lobed,” hence the name) screw for many of  it’s devices, so that they can’t be tampered with.  No matter, for $2 you can order a driver on line.  To the right, pentalobe compared with Torx, which is somewhat similar, except the stars have “points”.

PEN TESTING: Short for “penetration testing”.  Testing, usually by consultants(“white hat hackers”), to determine if they can penetrate the security measures you have taken to protect your computer(s) from intrusions and viruses.  Internal corporate pen testing groups are sometimes known as “red teams”.  Many former “black hat” hackers become legitimate "“white hat” consultants after being caught.  See, Hackers Hall of Fame.

PERISCOPE/PERISCOPING: Twitter’s live streaming app, introduced in April, 2015, which enables any user to broadcast live video captured by their smartphone’s camera to fellow Periscope users, also to promote the stream on Twitter to attract even more viewers.

P=NP (sometimes P vs. NP):  A formula which computer science theorists regard as a central pending theoretical question today.  [Actually, it’s one of the seven (now 6) “Millennium Problems” identified by the Clay Mathematics Institute. (It’s not a typo, it’s Clay not Cray)]  P = NP was introduced in a 1971 paper by mathematical theorist Stephen Cook of the University of Toronto, although it had been discussed for decades previously. Basically, it can be boiled down to this:  Does P (the problems that we can easily “verify”) equal NP (the problems that we can easily “solve”)? It’s not as easy as it sounds.  After all, it is easy to multiply two large numbers for a total and “verify” that the result is correct, but not so easy (maybe impossible?) to “solve” the result by starting with the product and working backwards to discover how it was computed.  This, then, is the theorem to be proved or disproved. 

In the formula, P represents the collection of mathematical problems that, say,  a computer can solve in a reasonable amount of time.  P actually stands for polynomial, representing a problem that only gets somewhat more difficult as the numbers get larger, as it proceeds in a linear fashion and because sometimes one answer simultaneously solves several others at the same time.  The other side of the equation, NP, stands for non-deterministic polynomial time, where the time needed to solve bigger problems quickly grows unreasonably (and exponentially) large.  The question is whether these two can be the same. Most theoreticians don’t think that P = NP, but they’re not absolutely sure about this, as it hasn’t been proven one way or the other. 

If proven correct, on the positive side, it would mean that there is an efficient way to calculate virtually everything, from the Big Bang Theory to a cure for cancer.   There is always a solution.  On the negative side, we should hope that it isn’t so, as most computer encryption routines hinge on the difficulty of factoring large numbers; the more complex the key, the more likely that it approaches the impossibility of being hacked, at least within a reasonable time.

My take on this is that it’s probably true, but that’s if you view it as a process, not a point in time.  Things that were viewed as “impossible” at one time become quite possible at a later time.  This is so because, over time, our knowledge has increased (due, for example, to advances in computer processing, to our discovery of our physical world, like understanding DNA, and a myriad of other factors, small and large) and will always continue to do so.  As we discover things like DNA sequencing, parallel computing, new species of plants and animals, new drugs and compounds and many other things, our ability to use this new information and these processes then permit us to solve problems which we previously thought were not possible or not possible within a reasonable time.  For example, we’ve already cured or reduced the severity of many types of cancer and, with the discovery of new tools and research results, we will most likely eventually cure cancer.  This would have been unheard of thirty years ago, seems possible now, and may well be solved twenty years from now.  Or the steady increase in computing power which has allowed us to create and run Rainbow Tables and Brute Force Encryption to break many types of encryption that were originally thought to be impossible, but are now child’s play to decode.   That would seem to prove P = NP.  To me, it’s a process.  But then there will always be problems for which the solution will always be out of reach as well. [But, then, I warn you that I’m relatively poor at math, so don’t listen to me for this type of stuff.  It’s just my personal understanding, not really the answer.]

The proof of my naiveté is that, even after 40 years, there is no answer in sight for this formula; if you do solve it, you can apply for the $1 million Millennium Prize from the Clay Mathematics Institute.

PENNY AUCTION (SITES):  As opposed to auction sites like eBay, which are free to bid on, penny auction sites charge a small fee each time a bidder bids on an item on the site, rather than a commission.  Each bid increases the price of the item by a small amount, such as a penny (and also extends the auction by a few seconds), hence the name “penny auction”.  Take Oklahoma-based QuiBids (also SwipeBids) which charges sixty cents for each bid on new items, not used ones, usually overstocks.  Or  But critics claim that there are lots of dangers in this type of bidding, and that it can be like a gambling addiction.  The cost of the bids can add up fast, the price and the time gets bumped up as well, and you may not win the product, only the right to buy it at the final price.

PERIPHERAL:  Any hardware connected (cabled or wirelessly) to the main computer (CPU).  This includes the monitor, printer, scanner, external drive, etc.

Periscope logoPERISCOPE:  A live video streaming app, founded by CEO  Kayvon Beykpour, launched in March 2015 and immediately snapped up by Twitter, later named Apple’s App of the Year for 2015. Basically, you open the app, click Broadcast, title the subject, then start recording.  Your Twitter followers can then follow your video feed.  Celebrities like Jimmy Fallon, Ellen DeGeneres, Donald Trump and others propelled the explosion of users of the app.  While it has competitors like Justin.TV, Ustream, Hang With and Meerkat, they just didn’t take off like Periscope.  In 2016, it introduced a new tool which will disable or ban users who post offensive comments during live-streaming video on the app. See Livestream on Facebook.


Perlman, Radia2PERLMAN, RADIA:  While employed by DEC, she invented STP (“Spanning Tree Protocol”), which is essential for the operating of network bridges.  She also influenced network design and standardization, including TRILL..

PERMISSIONS:  In the Windows O/S, software settings which determine whether a network user has access to a hardware device or software on that device and, if so, the extent of that access, providing network security.

PERVASIVE MEMORY SCRAPING:  A type of hacking of encrypted data, designed to capture PII (see below).  Usually occurs directly on the server, often internally through administrator accounts.  Where there isn’t end-to-end encryption, sometimes data resides briefly in volatile memory (RAM) and can be hacked from there.

open PGP logoPGP:  Stands for “Pretty Good Privacy,” an encryption program that provides privacy and authentication and which is often used for everything from e-mails to files and whole disk partitions.  Invented by Phil Zimmerman in 1991, it follows the OpenPGP standard (RFC 4880) and is widely used because of its relative ease and compatibility.

PHABLET:  Portmanteau of phone and tablet, i.e. a smart phone that is the size of a tablet.  One of the first was the Galaxy Note in October, 2011.

PHANTOM POWER:  See Standby Power.

PHASE:  Electrical current travels in waves which, when graphed, look much like sound waves.  These (sine, or repetitive) waves, like most types of waves, an be either in-sync (identically overlap each other) or out-of-sync (falling in between each other) between 0 and 360 degrees of each other.  Phase is the position at a given instant on that 360 degree waveform cycle.  It can also be an expression of the relative displacement between two or more waves having the same frequency.  Generally, the more phase(s), the more power.  Realizing that this isn’t particularly helpful, let’s look at the practical hardware aspects of electrical phasing: Single phase power power refers to a 2-wire alternating current power circuit, typically with one power wire and one single neutral wire.  Power load flows through the power wire into the neutral wire to create the circuit.   Dual Phase (sometimes called Split Phase) power has two 120 volt and one 240 volt power circuits which are 180 degrees out of phase with each other.  The 120V power flows alternating between either power wire and the neutral wire, while the 240v power flows alternates between the two power wires through the load.  Three Phase Power means that there are three power wires (Phases A, B & C), 12waves0 degrees out of phase with one another, and one neutral wire.  This provides three 120V single phase power circuits and one 208V three phase power circuit, where 120V power flows between any power wire and the neutral wire and 208V power flows between the three power wires.  Most houses require only single-phase power, while two phase power is for small commercial equipment and three phase is used for industrial facilities.  Three phase power saves on electrical construction costs for commercial buildings because of its reduced current requirements, smaller wire size and smaller and more efficient connected electrical devices, and the lower loss of electrical resistance through heat reduction.  See diagram from Stabl-Power and their site for more detailed explanation.  See also dirt, THD. logoPETS.COM:  A dot-com enterprise started puppetin August 1998, associated with the excesses of the 1990sIt was an online business selling pet supplies over the Internet.  While it became wildly famous for its sock puppet mascot, which appeared in the 2000 Super Bowl and had its own balloon in the 1999 Macy’s Thanksgiving Day parade, it lost so much money that it only lasted two years, failing in November, 2000.

PHANTOM POWER:  See Standby Power. Also vampire power.

PHISHING:  See Spyware.

PHONE:  See Telephone.

PHONENET:  An alternative cabling scheme using telephone wiring in homes for networking. Originally developed by Farallon Computing and first used for Apple computers, it has been mostly discontinuedSee AppleTalk.

PHOTO BOMBER:  Someone who either intentionally or unintentionally ruins an otherwise normal photo by, perhaps, making faces, gestures, getting naked, wearing a costume, etc., usually in the background of the photo.  Also, a TAG BOMBER tags a person in an ugly/awkward/compromising photo that they wouldn’t want others to see, uploading it to multiple social networking sites.

photoshop logoPHOTOSHOP:  An professional program from Adobe used for editing photographs and graphics that has become so popular that it is often used generically as a verb (“...that’s a Photoshopped photo”) to indicate a “doctored” image, like the ones of the “perfect” models.

PHP_logoPHP:  Stands for Personal Home Page/Forms Interpreter.  One of the original web coding programs.  The idea was that the PHP code would run before the page went out to the Internet.  It’s pretty much been superseded by other coding languages.  See also, JavaScript.

PHREAKING: Hacking, often old style (analog) telephone systems, especially to obtain free calls or tap into others’ calls.  The most popular phreaking tool is the “box,” such as the blue box, black box  (allows someone to receive calls which were free to the caller), red box and beige box, the color of which describes its function, generating a specific frequency of electrical signal.  The most popular, the red box, also the blue box, was used to make free calls from pay phones (no longer around), and could be assembled with a couple of parts from Radio Shack in about ten minutes.  The original and most famous phone phreak was John Draper, a/k/a Captain Crunch, who began phreaking on the West Coast in the 1960s (see Hackers).   No longer works in most countries and not useful with digital phone systems, which are the majority today.  See also Van Eck Phreaking, Tempest.

Picassa LogoPICASA:  A program that can be downloaded from the Internet which edits, organizes and shares photos over the Internet, acquired by Google and merged into Google+ as Google Photos in 2011.  The original logo represents a shutter mechanism, with the whitespace in the center depicting a house (the “casa” in the name) implying that it is meant for personal use, while the “pi” stands for pictures - “your personal pictures,” get it! Google discontinued the desktop version in 2016.

PICO:  Pronounced “Pee-Ko”.  A cellphone device or feature on a cellphone that can project photos (using laser technology), videos and graphics onto flat surfaces.  Not terribly bright (maybe only 5 lumens) and not terribly large (maximum 2-3 feet square at a maximum 6 ft distance), the technology is constantly improving.  Other than as a must-have-it-first feature for the Sharper Image crowd, I could see its usefulness to review photos where there is no computer or printer available, make an impromptu Powerpoint presentation to an important prospective client, or to watch a movie on the seatback of an airplane seat, but generally its overall usefulness escapes me so far, aside from the fascinating technology.  A similar device has been introduced by Blackberry, the “Presenter,” which is a separate bluetooth device plugged into a monitor or projector, eliminating complicated connections to a PC, and enabling the user to wander the room using the Blackberry as a remote (about $199 from Also, the Samsung HO3 projector (about $299).  UPDATE:  It seemed like it would be the next big thing, but never really took off. Why?  The display wasn’t all that good, it seems.  And it used up too much battery life.  Moreover, it was said that some worried about projecting porn in public places...

PICTOGRAPH:  A pictorial symbol which represents a word or phrase.  Prehistoric cave symbols were pictographs, also some icons, like the one for MS Word [MS Word Pictograph ].

PICOCELL:  Earth base stations which relay cellular signals through towers or satellites specially equipped to work with airplanes so that cell phone calls can be placed by users while in transit.

PICONET:  See, Personal Area Network, above.

PII:  Stands for Personally Identifiable Information. This includes such things as full name, mother’s maiden name, social security number, medical and employment records which, if released, could compromise your security.

PILCROW:  ¶ .  The typographic symbol or glyph used as the ”paragraph” symbol.  Also called the paragraph sign, paraph, or alinea.  It is used extensively in word processing and desktop publishing software, as well as in legal citation and proofreading.  As with many marks, its derivation is unclear.  Many say that it originally started with the letter “C”  (for capitulum or “chapter” in Latin) with double slashes through it, indicating the usual way that a scribe made his notes.

PIN:  (1) The tiny metal “feet” on the underside of a silicon chip (like a RAM, processor or video chip) that enable them to be attached toConnector pins a circuit board. (2) The short wires in certain male connectors (e.g. parallel, serial, power) which connect peripheral computer equipment (see photo at right).  (3) The Personal Identification Number which must be entered to obtain access to hardware and software.

PIN NUMBER:  Personal Identification Number:  A code that must be entered in order to access a program or computer.  Say, with Windows 10.  Keep in mind that the more digits in the PIN, the harder it is to crack.  A standard 4-digit PIN will have about 10,000 possibilities, not all that difficult for any dedicated hacker to unlock with software.  Add another digit, the possibilities increase to 100,000.  A sixth to 1 million.  The more the better!

PING:  A web utility that is used to determine whether a specific IP address is accessible, usually for internet troubleshooting.  It does this by sending a packet (ICMP Message) to the specified address and waiting for a reply. Ping’s author says that the name comes from “the sound that sonar makes”.  See loopback for a similar utility used with telephones. ALSO: an Apple social networking program through iTunes to a limited set of users, abandoned in 2012, which suffered from a lack of artist profiles and spam issues.

PINOUT:  A description of the purpose of the wires that connect to each pin of the connector to an electrical device.  An example would be the CAT wires that connect a cable to a punch down block.

PING POWER PIPE:  A colocation arrangement by which an ISP provides space, power and a link to a customer, all at their own facility. The ISP is only responsible for assuring that the servers are running.

PIO:  Programmed Input/Output - see DMA for a complete explanation.

PIPE:  A method of passing information from one computer to another, either in a network or over the Internet, through a temporary software connection. Some pipes are larger than others, influencing bandwidth.  Think of it like this:  If you have a tank with 100 gallons of water and you want to empty it, you have to consider the diameter of the pipe you will use to empty it in order to determine exactly how long it will take.  The faster, of course, the better.  So, if you use a 3/4 inch diameter pipe, no matter how much pressure you exert, it will still take an hour to empty the contents of the tank.  But, if you use a six inch diameter pipe, it’ll only take ten minutes.  The larger the pipe, the faster the speed.  It’s the same with computer bandwidth:  The larger the pipe, the faster the transfer speed.  That’s why the advent of cable, FIOS and DSL have made it possible to view streaming videos over the Internet without the “choppiness” that occurred when using the slower (i.e. smaller “pipe”) dial-up connections.

PIPE KEY:  A computer keyboard character (“ | “) which is a vertical line, also called a verti-bar, vbar, stick, think colon, divider line or vertical line.  It is usually found as the shift character above the backslash character on the top right of the keyboard characters.  It has various usages in computer programming and mathematics and is sometimes just a typographical divider.  The name for the pipe character is derived from its usage in Unix shells, where it notates the I/O Pipeline construct.  This character is not the same as the “(vertical) broken bar” (sometimes called a “parted rule”) unicode character    (“ ¦ “) which has a different mathematical and programming use and is rarely used.  The pipe is somewhat similar, however, to the Interpunct (“middle dot”) character (“ · “), which is often used as an interword separator, originally in Latin inscriptions (DONA ·EIS·REQVIEM) and also sometimes in the Mac OS X system and Unicode.

Pirate BayPIRATE BAY:   A website used for file sharing by some 30 million users, some say illegally.  Co-founder Gottfried Warg of the Swedish site was arrested in September, 2012.

PIVOT TABLE OR CHART:  This is a feature found in spreadsheet (e.g. Excel) and database (e.g. Access) programs which allows you to reorganize (“pivot”) selected columns or rows of data into a separate table or chart to view it from a different perspective.  It doesn’t alter the database itself, just changes the view.  Especially useful for viewing select parts of very large databases.

PIX:  A Microsoft app released in August, 2016 that claims to give the iPhone 6 and later a brain by using AI to take 10 photos each time the shutter is clicked, then choosing the best three (eyes not closed, no blurring) to present to the user.

PIXEL:  This is a contraction for “picture element”, which is a single point in a graphic image.  It is the smallest element of an image that can be individually processed in a video display system. Pixelpixel example1s can vary in intensity, size and shape and they are combined to display a graphic image. Sometimes pixel resolution is espressed in “dpi” (dots per inch) and dot pitch.   [See, e.g. screens.] If you continually enlarge a photograph, it will eventually display pixels, as shown in the photo on the right.  [From Dots, Spots and Pixels: What’s In A Name, by Kalliopi Monoyios, Scientific American (5/14/12)].

But it isn’t always the most important element in photo resolution.  See, e.g. How Digital Cameras Work.

PKI: Public Key Infrasructure.  See Encryption. This differs from the private encryption that you may use on your own (see Encryption) in that with PKI a public key is provided by some designated authority (a “CA”) as an encryption key that, combined with a private key derived from the public key, provides the encryption.  The use of combined public and private keys is known as asymmetric cryptography, allowing users of an unsecured public network such as the Internet to securely and privately exchange money and data.  See also, Code Signing, SSL, bits and bytes.

PK Zip logoPKZIP: A program used to compress files, usually for transmission over the Internet or between computers. See also, ZIP.

PLACECASTING:  Also known as Proximity Marketing. This is the wireless transmission of advertising content for a particular “place” over suitably equipped internet appliances, such as smart phones.

PLACEHOLDER:  The “blank” on a web page where a graphic would be displayed, but is blocked by user or site settings or slow transmission speeds. 

PLACESHIFTING:  Also known as SPACESHIFTING. The ability of allowing media such as video or music to be stored on one device and then accessed on another device usually through a broadband connection.  See, e.g. Slingbox.  The original placeshifting device has been attributed to TV2Me, developed by Ken Schaffer.

PLATFORM: The hardware and software configuration on a device that allows it to run a specific program.  For example, if you want to run Quicken on a laptop, you have to have a PC hardware configuration (Intel chip, RAM, etc.) and a Windows operating system which will be capable of running that particular program.  If you want to run Quicken on a Mac, you’ll have to have the right Apple hardware and OS 10 for that purpose.  A platform must be pre-existing, meaning it has to be available before the program is capable of being installed and operated.  In addition to computers, platforms can include other technologies, such as the Cloud, virtual machines and browsersCross-Platform means that the program can be used with, say, Macs, PCs & phones.

PLAYSTATION: See, PS, below.

PLC: Programmable Logic Controller.  A digital computer primarily used in industrial applications which is used to automate various electromechanical process, like controlling pumps in utility plants.  A frequent target of hackers.

PLENUM:  A type of cable (coax and twisted pair) meaning that it can be used inside walls, heating and a/c ductwork, suspended ceilings and raised floors where fire safety is a concern, as it will not produce toxic gas when it burns.  Click HERE for more.

PLESK: A software package used for commercial web hosting, providing automation for those tasks.

PlotterPLOTTER: A printer that makes line drawings like blueprints on large paper through the use of several automated pens.  Unlike other printers, a plotter can draw continuous point-to-point lines directly from vector graphic files or commands.  Plotters can be drum type, flatbed type or electrostatic.  Plotters were the first type of printer that could print in color and render graphics and full size engineering drawings, using CAD and CAE, but they are quite expensive.

PLUG-AND-PLAY:  See PNP. A feature of most Windows operating systems starting with Win95 which automatically configures peripheral devices and expansion boards without the necessity of further installation of any software.

PM: Private Message.  A conversation that takes place outside of a chat room or website forum, where you are chatting one-on-one outside of the group, so that the content is “private” and not viewable by the other group members.  When someone says they’ll “pm” you, it means that they will send a message to your message board account (e.g. on Reddit, if you’re using that service).

PMP: Stands for Project Management Professional, a certification (by exam) by the Project Management Institute which purports to be the industry standard for demonstrating competence and a solid foundation of project management skills.

PND: Portable Navigation Device, such as a smart phone or a GPS .

PNP: Plug and Play.  A part of the Microsoft O/S since Windows 95 that enables the operating system to recognize and install various hardware automatically, as opposed to manually.  Much more reliable than it was at its introduction, when it was dubbed “Plug and Pray”.  Do not confuse with Universal Plug and Play Service (“uPNP”) which is a way that Windows XP can detect new network resources, as opposed to local hardware resources.

POC: (1) Proof of Concept.  The determination that a certain idea or concept is feasible, but not a prototype, i.e. it hasn’t been created yet, but it’s possible.  For example, big data analysis could allow filtering by date, although it hasn’t yet. (2)  Also, Point of Contact, i.e. who you talk to in an organization.

POCKET DIALING (a/k/a Butt Dialing): A phrase used to describe those instances where someone has their cell phone in their back pocket and, when they sit down, the keys become depressed and unintentionally dial a preset speed dial number.  See LAWS about whether you are protected under privacy laws from disclosure of the unintended call’s contents.

POD: An acronym used for as part of the name for the Apple iPod which, according to Apple, stands for “Portable on Demand”.

PODCAST: A portmanteau of the words iPOD and broadCAST First promoted by Apple in late 2004 (but designed by Adam Curry (of MTV fame) and David Winer), it is a digital media file that is downloaded from a streaming Internet source onto a computer, then directly onto a digital media device like an iPod (hence the “pod” in the name) or other media player (like an MP3) to be viewed. It’s kind of like an online pre-recorded TV or radio program over the Internet.  Used originally to create “feeds” (subscriber downloads of updated information) from news and radio shows, it now extends to TV and even commercials.  Lots of websites have podcasts. Directories of some of these sites can be found at, Yahoo!Podcasts or Apple iTunes.  What makes them so popular is the ease of creating a podcast and the ease of regularly downloading them.   You have to subscribe to a podcast using a software program called a “podcatcher” or sometimes an “aggregator”.  The podcaster regularly checks the feed for any new content that has been posted and, when it finds it, automatically downloads it. Next time you plug in your MP3 player, it’s downloaded.  Further, most podcasts are free, can be replayed, don’t result in spam and are commercial free. And, you can always unsubscribe.  Despite the rise of social media, podcasting is still quite prevalent, but with the demise of the iPod in 2014, most users have bypassed the old way of downloading shows from iTunes and then syncing them with an iPod and instead load their programs directly via either Bluetooth-enabled cars or smartphones.  And revenue is becoming generated from listeners and even advertisers.  Listing of best podcast sites click HERE, best sites to host podcasts HERE.

PoE: Power over Ethernet.  poe_injector_exampleUsing ethernet cables to carry both data as well as power.  This is useful for powering devices such as cameras and wireless access points over long runs, particularly outside, where running a separate power cable would be inconvenient.  See, for example this PoE injector, a device which “injects (direct) power” into the cable, which would be placed ahead of the switch in an equipment room.  PoE is a subset of the 802.3 ethernet standard initially defined by the IEEE in 1983.  The original PoE standard (802.3af) was ratified in 2003 and supports up to 15W per port at a nominal voltage of 48V DC.  An updated standard (802.3at, sometimes known as PoE+) currently under consideration by the IEEE would increase the per port power capacity to 30W over CAT 5 and higher cabling.  See also, VoE.  The single cable reduces cabling, power supply boxes at outlets and service outages.

POINT: See also, Fonts.  A measure of type size, one inch equal to 72 points.  Because the measure is derived from earlier mechanical printing, the point size was actually derived from a measurement of the type body (the metal on which the type face was printed on) rather than the size of the type face itself.  As a result, the point size may substantially vary from one typeface to another, since not all typefaces occupy the same size type body.  For example, see the following variety of typefaces all shown in exactly the same point size:

POKE: A feature, later an iPhone app, from Facebook which sends a message (sometimes called a “digital wave”) which is visible for up to 10 seconds.  It’s similar to Facebook’s Snapchat service, available across all platforms.  See also, Snapchat, Blink.  Poke was discontinued in May, 2012, about the same time that Yahoo acquired Blink and closed it as well. FaceBook replaced it with its acquisition of WhatsApp in 2014.  See also TIP #84.

PokemonPOKEMON: A video game and card collecting franchise (later branching into TV shows, movies and anime) that captivatedPokemon_Go_screenshot kids in the early 1990s, inspired by creator Satoshi Tajiri’s childhood bug collection and purchased by Nintendo for worldwide distribution (they originally thought it was a long shot!).  In 1999, it raked in some $47 billion in revenue.  According to Al Kahn, the promoter who was responsible for distribution of the franchise (as well as Cabbage Patch Kids and Game Boy, among others), he named Pokemon (with the tricky accent over the “e” to make it more Japanese-y), which was short for “Pocket Monsters”.  Some things about the Japanese game had to be Americanized, such as the name of the game’s protagonist from Satoshi to Ash Ketchum and some references to Japanese history, customs and food, as well as the theme music, although the popular  Picachu (which in Japanese means “sparkle mouse”) remains.  On July 6, 2016, it was adapted and reintroduced as Pokemon Go by Niantic of Japan for interactive playing on cell phones using augmented technology, so that you can see an overlay of Pokemon “monsters” on your GPS locations, which you can then find (right next to real world objects) with your camera and GPS features on your smart phone and then capture (with “Pokeballs” (see screenshot at right)) and eventually square them off against one another in designated Pokemon “gyms”.  Also, a feature where users can take screenshots of Pokemon “in the wild,” as on your desk or with your kids.  The difference in the new game is that users have to get out in public and off their couches in order to detect the characters at various locations from cities to parks to businesses. These locations were imported from Niantic’s game Ingress (where users suggested locations), and they can show up anywhere from a playground to an operating room to a funeral, although some locations that may be deemed inappropriate can opt out.  This was the intent of the game designers, to get people out of their homes, but has also had a negative effect as players concentrate so hard that they walk into cars, ditches, even dead bodies, kill pedestrians while playing and driving, also collide with each other as they become engrossed in the game and trespass into places they aren’t supposed to visit.  And (believe it) robberies of players as they were targeted by thieves using digital “lures” designed to take players to fake “Pokestops” hotspots (locations to find Pokemon).  As it develops, you may see even more parallels to the old Pokemon game., which has an actual plot, TV, cards, hundreds of memes, etc.  Surely clones of this game will follow...

POLYNOMIAL:  Other than to say that it looks like what we think of as a formula, with lots of numbers, symbols and annotations, I can’t (yet) find a simple explanation for this term.  This LINK is pretty understandable.  Basically, it’s an expression (formula), composed of MULTIPLE terms (fixed numbers or variables (represented by letters or symbols) which are limited by exponents (which look like “squared” symbols) that limit the number of times tht the base number it is attached to can be used in the expression. As the link explains, a MONOMIAL, on the other hand, is a polynomial with just one term (e.g. 3x2); a BINOMIAL has two terms (e.g. 5x -1) and a TRINOMIAL has three terms (e.g. 3x + 5Y2 -3).  Polynomials are used in algorithms and other computer and mathematical computations.

POLYMORPHISM: No, it’s not a religious cult, outlawed in 10 states.  Rather, it’s technology that makes rootkits (See Spyware) almost impossible to find using ordinary anti-virus and spyware programsA polymorphic virus is one that changes its virus “signature” (i.e. its binary pattern) every time it replicates, and then infects a new file in order to keep from being detected.  Polymorphism techniques allow rootkits to rewrite core assembly code; the only hope for finding polymorphic rootkits is to use a technology that searches deep into the operating system and then compares the results to a known good baseline of the system.  Most anti-virus programs now have this capability built in, and there are other separate programs available as well. Also, UEFI, which is replacing the BIOS on most new computers, doesn’t have an MBR so it doesn’t get as many rootkits.  See also, FAQ #72, signatures.

PONG:  Often said to be the first video game (“pong” short for table tennis or “ping pong”), co-invented bPongy Nolan Bushnell through his company Atari (later the force behind the Chuck E.Cheese chain).  [Fact: Why did Pong use a square ball, not a round one?  Because it was cheaper to develop.]  Many who debunk Atari’s first place ranking say that Pong wasn’t the first home video game you could hook up to your TV or even the first video game of table  tennis - it was just the first commercially successful game that asked you for a quarter to play it.  Most experts point to William Higinbotham’s Tennis for Two game, a demonstration created for an open house at the Brookhaven National Laboratory in Long Island in 1958 as the very first true video game.  That was followed in 1962 by Spacewar!, designed by Steve Russell and his team at MIT, which was covered by Stewart Brand’s Rolling Stone article (photos by Annie Leibovitz, no less) about a Stanford tournament in 1972.  Moreover, the first home game console was not Pong, but rather the Magnavox Odyyssey, which had its own table tennis game, and went on sale in 1972, three years before Pong.  And Pong wasn’t even the first coin-operated arcade game, as that distinction went in 1971 to Computer Space.  My  personal bar favorite was Pac-Man, which also grossed millions and provided me with many happy hours at Houlihans.  In 2015, Americans spent almost $24 billion on video games (far more than the $11 billion for movie tickets).  Credit for most of this information to a 6/22/16 Washington Post article by Chris Suellentrop, which covered even more issues. 

.png: A type of graphics file format which preserve “transparency.”  That is, it is used to layer items without having a white box around the object. .png can be either interlaced or not.  Interlaced means that the file is saved with several resolutions built in to the file.  You will recognize such an image because, as it loads, it becomes increasingly clearer in seven waves.  Here’s an example of the difference between a .png and a standard .jpg file:  

POPCORN TIME:  A popular open-source app that is an interface which allows users to watch a vast selection of pirated movies that, it is said, will disappear from the user’s computer without a trace once it is viewed.  Actually it does leave “seed” files for others to download from the user’s computer.  The original developer, Four Times, got out of the business, but others have picked it up.  It is piracy.

POP3:  Incoming e-mail server. It’s where your mail is stored before it is picked up by the host (the part of the e-mail address to the right of the @ symbol).  POP stands for “Post Office Protocol” [a protocol is a standard way of communicating across a computer network, i.e. it is the “language” of the network].  The other most popular e-mail protocol is IMAP, which stands for Internet Message Access Protocol.

POP ROOM:  Point of Presence Room. Telecommunication areas (also sometimes called MMRs or “Meet Me Rooms”) which are prevalent in colocation centers which allow providers such as AT&T, Sprint or CenturyLink to physically connect to tenants providing transit service or Internet access. 

POPULATE: With respect to computer hardware, this means to plug in all chips and other components onto the main circuit board.  A “fully populated” board is therefore one that contains all the devices it can hold.  Respecting software, it means to incorporate all of the necessary information into a program so that it can perform its function.  For example, in order for a database to execute and produce a report, it must first be populated with all of the raw data required to define and then execute that report.  See Boards.

POP UP:  An annoying advertisement that “pops up” on a computeEthan Zuckermanr screen when a user clicks on a web address of part of a web page.  Invented by Ethan Zuckerman, who wrote the code while employed at at in the mid-1990s.  He’s now the head of the Centre for Civic Media at MIT and has actually apologized for his contribution.  The invention of “pop-up blockers” pretty much ended their reign.  See also Banner Ads.

PORT:  This term has both a software and a hardware definition. 

When applied to hardware, a port is generally a specific place for a physical connection between the main computer and a peripheral device (See, PCI, above).  Most computers can have a maximum of 3 parallel, 4 serial, and 2 PS2 ports, although newer computers may have none of these, only USB ports, and others may have firewire or thunderbolt ports in addition.  DOS assigns the names LPT1, LPT2 and LPT3 to the parallel ports, which are usually used for printer (the designation LPT actually means “Line Printer”). The pseudonym for LPT1 is PRN, the first and most common printer port.  COM1, COM2, COM3 and COM4 are the DOS names for the serial ports (COM means “communications” port).  USB (Universal Serial Bus) ports are called USB ports; there can be (theoretically) up to 127, practically now more than 6.  PS2 ports are used for keyboard (purple) and mouse (green) connections, so called because these ports were introduced in 1987 with IBM’s Personal System/2 line of computers.  You should consider the number and type of ports when building or purchasing a computer.  For more on this, see the discussion at CASES.

Respecting software, a port like a “slot” that programs can use to create or accept connections to be used on that computer.  There are 65,535 ports available on each computer.  Such ports can be Open, Closed or Stealth (closed and completely invisible to outsiders).  Ports have assigned numbers, between 0 and 65,535, as assigned by the Internet Assigned Numbers Authority (“IANA”) and are divided into three ranges:  Ports 0 to 1023 are always reserved for use by the IANA, are known as the Well Known Port Numbers, and include standard default ports like HTTP (port 80) used to download web pages, port 110 (used to download e-mail), FTP (port 21), SSH (Port 22) and SMTP (port 25).  The second range is the Registered Port Numbers, containing Ports 1024 through 49,151, generally assigned to be used by ordinary programs and user processes that are executed directly by users.  The third range is the Dynamic or Private Port Numbers, ranging from port 49,153 through 65,535, generally for use by applications and processes not initiated by the user.  Because of this, the upper port range has often been used by Trojan Horse and Back Door programs (see Spyware) and is usually blocked by administrators. Most ports are designated as either TCP or UDP.  TCP ports are used for such things as web sites and e-mail.  UDP ports  are used when a transmission doesn’t need to have confirmation that a packet has arrived at its destination.  For example, in home networks, UDP ports are used mostly for home gaming (for example, Xbox uses UDP ports 88 and 3074 to connect with the Xbox Live Service).  Normally, a port is closed when there are no system services using it or listening to it, protecting your system from outside attacks.  But there are always malicious hackers who can find a way in, so additional protection (hardware and software firewalls) may be advisable.

There are standard software ports used for cell phone transmission, and they vary by both the ISP (e.g. Verizon, Comcast), server (if you have a private domain server) and even the cell phone manufacturer (e.g. Motorola, HTC).  There are, however, some general settings that cover most of the common cell phone ports:  Click HERE for a listing. 

PORTAL:  A term, pretty much synonymous with Gateway, for a World Wide Web site that acts as a major starting point or “anchor site” for users when they connect to the Web, creating a single point of access to information connected from many sources.  Portals can be divided into general portals such as Yahoo, Excite and the like and niche (specialized) portals, such as &

Humpty DumptyPORTMANTEAU:  A word which is actually a combination of two or more words or parts of words (“morphemes”), having its own separate meaning.  Like “fog” + “smoke” = “smog”.  (See Glossary for more about this.)  The history of this term is interesting, at least to me:  It was first used to describe a piece of English luggage which contained two equal sized compartments in a single piece of luggage, so that travelers could pack certain items, like winter coats, separately.  The word itself is derived from the French “porter” (“to carry”) and “manteau” (“coat”).  It’s first major use was probably by Lewis Carroll in his book “Through the Looking Glass”), written in 1871, in which Humpty Dumpty explains to Alice the strange language in Jabberwocky, such as “slithy” (meaning  “slimy” + “lithe”), telling her “You see it’s like a portmanteau - there are two meanings packed up into one word”.


POS:  Point of Sale.  Refers to devices and software that are present at the location where sales are completed, such as at cash registers and checkout points.  The type of systems that are used at POS will vary, but include electronic cash registers, computers and credit/debit card scanners.  See also, PCI DSS, above, and EMV.

POST: Power On Self Test.  A diagnostic test sequence run by a computer’s BIOS, after the power is turned on, which determines if the computer’s RAM, drives and peripherals are working and, if so, allows the computer to boot.  The POST test is accompanied by a series of long and short “beeps” which indicate whether or not specific hardware is working or failing; the interpretation of the beeps varies with each manufacturer of the computer’s motherboard.  Secondary meaning: A public message sent to a blog, as in a comment to the original post (part of a  “thread” of posted comments), is a “post”.

POST: An integral part of the BIOS (but not in UEFI) which stands for Power On Self Test, the purpose of which is to detect the computer peripherals such as the keyboard, RAM, printer and other hardware, as well as the hard drive, and determine that it is running properly, before permitting the computer to load the operating system.

Postini logoPOSTINI: Sounds like some sort of Italian cracker. A crostini with pimento, perhaps?  No, it’s not.  It’s actually a variation of the Italian word for “postman”.  Postini is used to indicate a type of e-mail security which is distinguished because it filters the e-mail before it reaches the destination box.  It is used mostly by companies which manage their own e-mail servers.  Named for the electronic mail security company, founded in 1999, based in San Carlos, California bearing this name.  It was purchased by Google in 2007 and is now used in Gmail.  It is a “hosted” service which doesn’t require the user to install any special software or hardware, as all the incoming and outgoing data is hosted and processed on the Postini servers first.

POSTSCRIPT: Also, Encapsulated PostScript.  See FONTS, above.

POTS: Stands for “Plain Old Telephone Service”.  Your basic old fashioned wired land-line telephone service.  Copper wires (see AWG), no DSL, no FIOS.

POTS: Telephone slang for “Plain Old Telephone Service”.  Refers to the old analog “land line” phones.

POWER: Whether it’s a battery or house current, this is what powers a computer.  [Increasingly, you can obtain charging power wirelessly, see Wireless Charging.  And PoE, above.]  Power management, found in the Control Panel, is also one of those settings that computer users forget to customize.  Similarly, when power issues arise (machine shuts down or restarts without warning or won’t wake up from hibernation), these are sometimes indicative of issues with your computer’s power state-management subsystem, typically defined by the Advanced Configuration and Power Interface (“ACPI”) specifications.  Luckily, starting with Vista, Microsoft offers various diagnostic and repair programs to solve these problems, although it’s best to check on-line or with your specific computer manufacturer to see if this is a known issue with a known solution.  The “Troubleshooters” for “Power” found in the Troubleshooting section of the Control Panel and more on the Microsoft site can be useful.  Also, you can try “sfc /scannow” or going into the hardware drivers (e.g. network adapter) to make sure that they’re not checked to “allow the computer to turn off the device to save power”.  As a last resort, if you’re up to it, use the “powercfgcommand-line tool to manually re-configure the power environment for your computer.  If nothing works, you may have to reinstall the O/S.

POWERLINE: A type of networking characterized by adapters which plug into electrical outlets to connect the network hardware.  See this LINK for more.

POWERPOINT: See, Microsoft Office.  Arguably the best and the worst thing to happen to corporate presentations in the past 25 yrs.  In 1987, Dennis Austin, Robert Gaskins and Tom Rudkin of Forethought, a CA software company released a $395 package (for Macs only) for making spiffy presentations.  Microsoft purchased the app in 1990 for $14 million and it now globally dominates the entire market for slideshow presentations.  Even bad ones.  But there are others - Sway (a Microsoft app suited to Office 365 collaboration); Google Slides (particularly useful if only a smart phone is available on the fly); Visme (another web-based app); Venngage (more graphics based); and Prezi (an innovative app that “drills own” from the general to the specific in its presentation.


POWERSHELL: You may remember that in early versions of Windows, there was a blank “Run:” line at the bottom of the Start Menu, as well as a “DOS Command” selection on the menu list (the so-called “DOS Box”).  That was there so users could write text-based commands to edit the operating system.  Examples of the DOS commands are listed HERE.  Those commands were a DOS “shell,”  sometimes creating “batch” files used to accomplish certain tasks.  As Windows evolved from the old text-based menus into today’s common GUI, something more had to be invented in order to allow editing.  In 2006, Microsoft created a new shell and associated scripting language (VBScript, actually), originally dubbed “Monad,” quickly changed the name to PowerShell.   Powershell is the Windows based version comparable to the old DOS-based batch language, and while both of which let users automate and manage many administrative tasks, PowerShell is capable of doing exponentially more. PowerShell does this through the use of “cmdlets”  for the most common commands, like creating directories, copying, moving or renaming files and the like.  Examples of the ten most common PowerShell commands may be found HERE.  It is inevitable that many computer users will end up using some type of PowerShell scripting, as Windows progresses toward more automation.  For the time being, in Win 8 & 10, for example, one can restore the old Command Prompt by unchecking the box in the Taskbar and Navigation Properties window after pressing the Windows + X keys.  Luckily, for those of us who really aren’t interested, there are lots of online course and tutorials available to make the transition easier if need be. In 2016, Microsoft made Powershell open to developers..

PLC: Programmable Logic Controller - A digital computer used for industrial automation purposes such as controlling machinery in factories.  A frequent target for hackers, who attempt to control power and water plants.

POWER SUPPLY (“PSU”): You may plug your computer into the wall in your home or office, but it doesn’t really run on 120 volt current.  It usually runs on 12 volt/12 amp current, but different systems can vary.  The hardware that converts alternating house current (“AC”) into direct low voltage current (“DC”) is called the power supply unit (or “PSU”).  You can stop reading here, unless you want to know how the PSU actually works...

Depending on what size your computer is, the power supply is generally a small, square metal box with an external plug for the incoming household current and various sizes and groups of wires, cables and connectors, designed to be attached to the motherboard and various types of drives, DVD players and other devices on the inside of the case.  Depending on the type of motherboard (e.g. ATX, AT, etc.) the size and type of connectors will vary (see ATX slot in motherboard photo on RAM page).  Most PSUs have either 20 or 24 pin plugs into the motherboard, plus a 4 or 6 pin power connector, and multiple molex and/or SATA power connectors and SATA and/or IDE drive connectors. Power supplies can be either modular, semi-modular or non-modular.  The primary difference is that a modular PSU has detachable cables, so that you only need attach those cables you need.  A semi-modular PSU has only the bare minimum cables attached, leaving the rest up to you.  A non-modular PSU arrives with all cables attached, you can tie up those that you don’t require. (Inside the metal box resides a transformer (which reduces the voltage from 120v to 18v AC), a rectifier (which converts the 18v AC to 18v DC) and then a filtering capacitor (which evens any voltage fluctuations), as well as a cooling fan.  In order to reduce the size of the unit, switching technology is used to optimize the power conversion.  (In some laptops,  to save space, the transformer is actually that little black box between the power plug and the computer.)  This technology converts the 60Hz frequency of household current to a much higher frequency and makes it much easier to filter as well.  Depending on the power necessary to run your computer, however, the wattage of the power supply can vary from 300 - 900 watts or more.  Go to cases to see how to calculate the wattage for a power supply and why it has to be higher at boot than during normal operation.  [Click HERE for explanation of electric terms like volt, watt and amperage.]  Photos below, left to right: power supply (external), power supply (internal) and in case (top left).

power supply in computer case
power supply interior
power supply exterior
Power Symbol

POWER SYMBOL:  Back in the WWI days, engineers used symbols for “on” (“1”) and “off” (“0”).  About 1973, the International Electrotechnical Commission created the symbol to indicate “standby power state,” merging both the 1 and 0.  Now it just means “power” and is on virtually all electronics around the world.

power whip2POWER WHIP:  Industry slang for a power cable or conduit that runs from a building’s electrical box or power pole directly to a device like an air conditioner, light fixtures, or other item of electrical equipment requiring power.  It usually has a specialized connector at the end connecting to the device.

PMPO:  A value is often listed as "watts PMPO" on speaker and other product packaging. It is the acronym for Peak Music Power Output. The alternative to PMPO is RMS (Root Mean Square), which is the precise mathematical rendition of a speaker's power output. RMS is a statistical representation of the average power output of the speakers. PMPO is the peak power and is a larger number as compared to RMS which is an average. The PMPO was initially mentioned in the product packaging just as an marketing strategy to show a larger power number.  After all, consumers will think that larger is better!  See speakers, RMS.

PPP: Click HERE.

PPPoE: Click HERE.

PPSD: Stands for “Personal Portable Security Device”.  Combines the flash storage of a USB pen drive with the access and secure storage capabilities of a smart card, using cryptographic encryption and strong user authentication.

PREDICTIVE SEARCH: A search which lists suggestions as you type the query.  As you continue typing, the suggestions become more and more specific.  See, e.g. Google Now, Apple Siri.

PREDICTIVE TYPING: A smart phone operating system feature that attempts to identify the next word you want to type based on what you’ve written in the past, letting you add it with a single tap.  Google calls it  “QuickType”.  See also SWYPE.

PREDIX: An internet industrial operating system developed by General Electric, which “combines cutting-edge technology and decades of industry experience into a platform that securely ingests machine-grade data at scale and analyzes it to deliver outcomes very fast”. It’s a PaaS, highly optimized for industrial internet applications, differentiating itself by using a microservices architecture model where applications are created as a catalog of services (making it easier and faster to change and maintain apps) rather than as one tightly coupled monolith code, which is slower and less adaptable. 

PRE-ENCRYPTION: The process of encrypting files in advance of transmitting them for storage in the cloud.  That way, if your files are compromised while on the cloud server (e.g. SkyDrive, Google Drive, Dropbox), even though the server is also protected by encryption, all that an intruder would get would be gibberish and your data would be safe.  If you have Windows Pro, Enterprise or Ultimate, EFS (“Encryption File System”) or BitLocker may already be built into Windows by default; if not, try Boxcryptor.  For more, see encryption.

PREFETCH: A file in Windows and other programs into which data or instructions, often when downloaded off the Internet, are placed into higher-speed storage or memory before they are actually processed.

PREVIOUS VERSIONS (WINDOWS FEATURE): A feature in Windows 7 and later which makes use of the change journal of the computer’s NTFS file system  (which records all changes to files and folders on your hard diskdrive) to enable users to restore existing files backed up in the Libraries, Desktop, Contacts and Favorites folders.  Kind of like restoring files from your Recycle Bin before it’s emptied.  Really, though, it’s more like creating an external file backup with any other independent program, but Windows is doing it automatically.  [For deleted files, see below.]  For example, in Windows 7, just locate a file in Windows Explorer, right-click it, select Properties, then click the Previous Versions tab, where you can click on any available previous versions.  But, in order to have older versions available, they must be saved via Windows Backup or through the automatic System Restore feature, so make sure you have one of these two sources.  If you do, your backup files will be stored on the same hard drive as your computer system.  Win8 (and Win10) came along and changed the whole procedure.  Now the feature is renamed File History and it’s a little more work, but considerably more customizable.  But it won’t store the files on your hard drive any longer; it requires an external (or network) drive which, of course, must be continuously attached (not usually a good thing for USB external drives, I’d install a second hard disk drive in the computer if I could).  First, you have to direct File History to a location on an external drive, where you will then back up your files automatically.  This is quite useful if you have a network with several computers, as you can direct all of their file backups to the same drive location, almost like NAS.  Restore the files by right-clicking a file, going to Properties and using the options on the File History tab.  Two things you should know:  System Restore no longer keeps backup files like it did in Win7.  And File History is not enabled by default, and must be enabled (Control Panel>System & Security>File History).  Win10 continues this same procedure.  But you still have choices to make - the usual dilemma of convenience vs. security - If cryptoviruses are a concern, you’ll have to detach your external drive when you’re done backing up, or else make a snapshot backup, otherwise the virus will infect and render useless any attached internal, cloud or external drives, rendering your attached backup useless.

What if you have deleted the files?  First try the Recycle Bin, it’s the easiest fix.  If the file isn’t in there, you have to at least have access to the folder in which the deleted file resided.  Go to that folder, right-click it and then go to the Previous Versions tab, where you can choose from the previous versions of the folder, open it and see a complete listing of the files that were in the folder at that time, from which you can select the desired folder (ignore the security message).

Not to be left out, Macs have features for this as well.  Versions works with many Mac apps if set up, after which you simply click on File and point to Revert ToTime Machine can serve this purpose as well.

Linux is less friendly and doesn’t automatically include O/S tools for this purpose.  But if you’re lucky, the Backup tool (a/k/a Deja Dup) if used may allow recovery of some files.

Finally, if you use other backup programs, those independent of the operating system like Acronis or Easus (see Backups), they have their own ways of restoring older versions of backed up files, not greatly dissimilar from those discussed above.

This discussion purposely ignores Cloud versions of files, created with apps like Google Drive or DropBox.  They’re not on your computer or drive.  Also, those files aren’t kept in the cloud forever and may disappear (or some older versions of files may also disappear if there are several) depending on the cloud app. 

Restoring is similar to the apps discussed above.  It’s not only an excellent way to restore different file versions, but also to recover files if the original hard disk drive has crashe. Since the restore feature can sometimes replace the file without asking if you’re not familiar with the procedure, it’s always a good idea to select another location to restore, that way you’ll have both copies of your file accessible on the hard drive.  You can always erase one or revert the file.

PRI: Primary Rate Interface.  See cell phone definitions for more.

PRIME NUMBER: A whole natural number greater than 1 that cannot be divided by anything other than 1 and itself.  The first few prime numbers are 2,3,5,7,11,17...and they become less frequent as the sequence continues.  All numbers that are not prime numbers are called composite numbers. 

PRINTERS: Generally, any piece of computer equipment which prints text or graphics, or both, onto paper of other media.  Click HERE for more information.


PRISM: A NSA surreptitious surveillance program developed in 2007 allowing the U.S. Government to tap into the servers of at least 9 major ISPs, revealed in June, 2013 as a result of documents disclosed by newspapers The Guardian and The Washington Post.  See LAWS, Carnivore, Echelon, Palentir, NSA, and Bitmessage for more.  The NSA Powerpoint presentation slide below describes the extent of the program:

PRISM chart

PRISMA: A popular creative photo app that “redraws” smart phone photos imitating the styles of 33 famous artists.  It is not a “photo editing app” like Instagram, which tweaks an existing photo.  Rather, it uses an AI technique called neural network processing, which uses interconnected algorithms to generate an entirely new image by “reacting” to one the user provides (rather than the old way, by complying with specific user-given commands).  It detects patterns both in the image (which can come from anywhere in the public domain) as well as that of the selected artist, then uses the rules pulled from these patterns to generate a third, combined Prisma photoimage.  It usually takes less than 15 seconds or so, and it can then be shared via FaceBook or Instagram, if you choose to do so.  It is available in iPhone and Android versions.  It was developed by Alexey Moiseenkov of Moscow (formerly employed by Mail.Ru, a Russian internet company) and his 9 person team.

PRIVACY: With the exception of certain specialized areas (e.g. patient records), there is NO RIGHT OF PRIVACY ON THE INTERNET.  Especially from the Government.  See Social Networking, Laws, Big Data, Security, Privacy, Watched, etc.  Click HERE for more about blocking ad trackers.

Privacy Badger beta logo Privacy Badger:  A plug-in from the Electronic Frontier Foundation (see Associations) for Chrome and Firefox browsers which blocks third-party tracking, including the Facebook “Like” button.  EFF claims that this blocker is different from Disconnect, AdBlock Plus and Ghostery because it operates automatically, without custom configuration.  Click HERE for more.

PRIVATE BROWSING (or INCOGNITO) MODE: Also euphemistically known as “porn mode”.  A feature on some browsers that allows the user to browse in a session that does not save any data (e.g. history) from the browsing session.

PRIVATE EMAIL: E-mail that is encrypted directly, through an app or browser extension, so that it cannot be privately snooped. Click HERE for more.

PRIVILEGE: Sometimes also called “Permission.” A permission to perform an action or grant access on a computer system, i.e. access a drive or a printer.

PRNG: Stands for cryptographically secure Pseudo Random Number Generator. It was developed by Bruce Schneier and Niels Furgeson and is named after and sometimes also called Fortuna, the Roman goddess of choice .  PRNG is composed of three sections:  The generator itself, the entropy accumulator, which “reseeds” the generator by collecting genuinely random data, and the “seed” file itself which enables the computer generator to work.

PROCESSING: The use of a computer to manipulate data (words, numbers, etc.) according to instructions (a program) to achieve a desired result (information).

PROCESS: When you look in the Windows Task Manager and see a list of “processes,” for example, it simply means a list of programs that are running at that time.  It may include many executable programs that you may not understand, as they may be part of the operating system, but they are programs.

PROGRAM: Generally, the term refers to application software for end users. See, Applications.   Specifically, a program is a set of instructions that a computer uses to process raw data into useful information.  For example, the  accounting program Quickbooks processes raw financial data into reports.  For more about how programming works, click HERE. Programs can generally be divided into “low level” (e.g. machine language compilers) and “high level” (e.g. end user programs like C++).

PROCESSOR:  The so-called “brain” of a computer.  That is, the logic circuitry that responds to and processes the basic instructions from the operating system that drive a computer.  This term has generally replaced the term CPU (see this link for more).   The “chip” that is embedded in the processor circuitry that is the brains of the processor itself is often called the “microprocessor.”  Computer processors can generally be characterized as either “scalar” or “vector”.  Scalar processors process only one datum (e.g. integers or floating point; see numbers) at a time, classifying them as SISD (single instructions, single data) types, while vector (a/k/a “array”) processors (SIMD or Single Instruction, Multiple Data) can process instruction “sets” on arrays (groups) of data at once, making them faster and more powerful, especially for gaming computers and high speed graphics accelerators.

PROGRAMMER: Someone who writes instructional code into programs to be run by computers.  See coders for more.


PROMIS: Software (Prosecutor’s Management Information System) developed by Inslaw, Inc. in the early 1980s for the U.S. Dept. of Justice, originally to keep tabs on prosecutors’ caseloads, but which allegedly morphed into spy tracking software.  The DoJ allegedly put Inslaw into bankruptcy and stole then modified PROMIS with backdoor capabilities for covert intelligence operations.

PROPRIETARY: Describes something held exclusively by a person or company, as in “Apple has proprietary rights to Airplay, which must be licensed from them for use by anyone else.” The opposite of open source.

PROPS: A slang verb meaning “proper respect”.  For example, “We’d like to give props to all those who made the Superbowl halftime show successful!”

PROTOCOL: The “language” (actually, more like a set of communications standards or rules) used by a network for communicating across the network.  For example, TCP, BGP and POP3 are protocols.   [To get an idea of the hundreds of protocols in use, click HERE for a directory listing of common protocols.  See, e.g. SDN]  Protocols had to be developed in the early days of computer communication in order to prevent too many proprietary ways of sending and receiving data over the Internet, thus “standardizing” network communications for everyone.  The two main protocols used over the Internet are TCP and UDP (see ports, above); also sometimes  RAW or ICMP.  In the early days of the Internet (i.e. the 1980s and 1990s) “multi-protocol routing” was used for IPX, AppleTalk and TCP/IP running on the same network.  TCP/IP was favored because it uses a very simple four-layer model (i.e. Application, Transport, Internet and Link layers), vice the OSI Model conceived in the 1980s, which has seven layers (see the OSI definition).  Because the Internet has been constantly evolving since the 1970s, TCP/IP has also evolved from its original design, adding security while optimizing throughput forwarding performance.  Some of the most common additions are Multipath TCP  (“MPTCP”); TCP AnyCast; HTTP/2; Quick UDP (QUIC); HTTP Strict Transport Security (HSTS);  Datagram Congestion Control Protocol (DCCP); Structured Stream Transport (SST); Stream Control Transmission Protocol (SCTP); Datagram Transport Layer Security (DTLS); Secure Real-Time Transport Protocol (SRTP); and Reliable User Datagram Protocol (RUDP)

PROXIMITY MARKETING:  See, Placecasting, above.

PROXY SERVER:  A form of firewall.  A proxy is someone who performs some action on your behalf; a proxy server performs network transactions on your behalf, most commonly web transactions.  The proxy server will take requests from your web browser, then get the web pages from the internet on your behalf, and return them to your browser.  Because the proxy server can perform authentication to see who is requesting the web pages and logs the pages requested, it provides some level of protection. Unfortunately, some viruses insert their own proxy servers in between your browser and the internet, so you can’t get to the internet to remove them.

PS: Stands for PlayStation, usually with a version number at the end, such as the current version, PS4, released on 11/15/13. UPDATE:  The Playstation VR, released in 10/16, adds virtual reality capability.  First released in 2006 and now part of the seventh generation of video gaming consoles, PS3 is produced by Sony, and competes with Nintendo’s Wii and Microsoft’s Xbox.  A significant distinguishing feature of PS3 is the PlayStation Network, a unified online gaming service which relies on players, as opposed to professional developers, to contribute to the games, as well as the ability to use Blu-Ray disks. The Vita version, introduced in 2012, combines the gaming console with social networking in a smart phone interface.  And Sony is working on Playstation Now, which streams games from the cloud, without the necessity for special hardware or televisions.

PSA: Public Service Announcement (or Ad):  Public interest messages disseminated by media (radio, YouTube, TV, even Twitter), usually without charge.  They can be about women’s rights, Ebola, civil rights or the like.  The range of topics has expanded recently along with the expansion in social media.

PS2PS/2 Port:  A computer (motherboard) connection port for keyboards and wired mice, which is a Mini-DIN 6 plug (which replaced the DIN 5 “AT” connector plug) and the 9-Pin serial port connector, which was also used to connect some mice.  These days, most keyboards and mice connect via USB ports.

PSEUDOCODE:  A detailed yet readable description of what a computer program or algorithm must do, expressed in a formally-styled natural language (say, English) rather than in a programming language. A substitute for a flow chart logic diagram.  Once the pseudocode is accepted, it is rewritten using the vocabulary and syntax of a programming language (e.g. C++) or as an algorithm.  

Example:  Pseudocode to verify the accuracy of a calculation adding 2 numbers -

> Take the first whole number to be added; then

> Add up the sum of its digits; then

> Continue to add up the digits until only a single digit remains; then

> Do the same for the second number to be added; then

> Do the same for the sum of both numbers; then

> Add the single digits together for the first and second numbers; then

> Compare the line above to the single digit for the sum of both numbers; then

> If the digit for the calculated sum matches that for the two numbers, it is correct. 

> If the digits do not match, the calculation is incorrect.  Recalculate.

[Click HERE for more about RSOD.]

Note that the pseudocode is in plain English, says what the code is to accomplish in a step-by-step set of instructions.  Expressed as an algorithm, it would look like a mathematical formula, using symbols and variables.

PST FILE:  MS Outlook data files (PoST office?) used for archiving up to 2Gb messages in that program.  They are stored on individual computers as Outlook doesn’t support network storage and contains all of the data (messages, address books, etc.) for each Outlook identity.  They can become corrupt and unstable as they get larger and aren’t archived.  Also, because they can result in individual archiving of older messages, they aren’t secure and may cause problems with archiving compliance and legal discovery.  Best for individual users.  Exchange is better for enterprises

PSTN:  Public Switched Telephone Network, i.e. the “Telephone Company”.  See DEMARC.

PSU:  Power Supply Unit.  See Power Supply, above.

PTE:  Page Table Entry. A 32-bit entry into the Windows paging file table which defines the mapping of virtual memory to physical memory. See Page File, above.

Public vs. Private:  Click HERE for a discussion of public and private IP addresses and how they operate.

PUBSTRO:  Refers to a computer that has been hacked and had an FTP server installed.  The FTP server is then used to transfer and spread WAREZ (copyrighted software), usually illegally.  It does this by scanning broad IP address ranges with port scanners in search of open ports vulnerable to attack by various scripts, which are used to create logins to transfer the warez.   Click HERE for a more graphic explanation...

PUCK:  An input device used with CAD-CAM software that looks like a mouse with a magnifying glass attached to the end, with crosshairs on it, used for precise positioning when drawing.

PUE:  Power Usage Effectiveness.  A standardized measurement comparing how much of the total energy in a data center is used by the IT equipment compared to how much is used for heating, cooling, lighting and other infrastructure needs (i.e. total facility power divided by IT equipment power) with 1 as a perfect score (meaning that  all data center power would be completely consumed by IT hardware, with absolutely no waste).  Used by large IT organizations to determine energy consumption and reduce the cost.  Many large companies score as low as 1.2; Google has reached 1.15 in some locations.

PUNCH CARD (a/k/a keypunch card):  Invented in 1884 by Herman Hollerith (a German-American statistician) of the Tabulating Machine Company, which was joined by Thomas J. Watson, Sr. in 1914, and which subsequently (1924) became known as IBM.  [It’s been verified (and IBM has never denied)  that, through punch cards and their sorting machines, IBM assisted the Nazis at every stage of their purge by sorting census data to identify Jews in order to keep them out of particular fields of endeavor and also by identifying where Jews lived and their family members, so that they could be evicted from their homes then forced into the concentration camps, almost all of which had “Hollerith Departments” for efficiency. See “IBM and the Holocaust: The Strategic Alliance Between Nazi Germany and America’s Most Powerful Corporation,” by Edwin Black, Crown Books, 2001, for the full story.]  Punch cards are sometimes called, in fact, “Hollerith Cards”.  A stiff paper card, about 90mm x 215mm, commonly having 1 character per column and 80 columns per card, onto which were punched rectangular holes (“chads” being the paper bits cut out of the holes, remember the 2004 “hanging chad” problem with the tabulation of the Presidential election?) to represent letters, numbers or code, were read by a computer, through a “reader” with a large card “hopper”, in order to process data.  Because holes could corrupt the data to be read, they usually contained the printed warning not to “fold, spindle or mutilate”.  (The myth that the cards were rectangles so that they fit into cash register drawer trays was disproved.)  Hollerith invented and patented the punch cards in order to create a machine to tabulate U.S. census data more efficiently than the hand methods used up until his invention.  His great breakthrough was his use of electricity to read, count and sort the punch cards with the relevant census data, so that the machines, which were first used for the 1890 census, accomplished in one year what would have taken nearly 10 years by hand tabulation (See below).  He got the idea from combining the idea of a train conductor punching tickets with a machine created by a French silk weaver named Joseph-Marie Jacquard, which automatically controlled the warp and weft threads on a silk loom by recording patterns of holes onto a string of cards.

hand punch card machine

From left to right:  Punch card, hand punch card machine, electric punch card machine, punch card reader

Holletith card reader

<  A replica of the Hollerith Electric Tabulating System that was used to  process punch cards in the 1890 census. In all, 60 million cards were  processed with these machines.

Spindle for bills
do not fold

< You don’t see these any more, but this is a spindle.  It had a sharp point and you stored bills, lists and receipts on it until you filed them or threw them away.  Hence the phrase “Do NOT fold, SPINDLE or mutilate” the punch cards!  They went the way of eyeshades and armbands on accountants.  If you don’t remember, don’t ask...

PUNCH DOWN BLOCK:  (Also, punch block, or quick-connect block, module or jack).  A type of termination electrical connection used in computers and telephones in which unstripped solidpunchdown block copper cable wires are literally “punched down” with a special tool into short open-ended slots known as insulation-displacement connectors (“IDCs”).  They are used because there is no stripping of wiring, connectors to fasten or screws to loosen and tighten.  For photos and more definitions, see 66/110 Block.  See also CAT.  There are different types of punch down blocks, the most common of which is the keyKeystone in architecturestone strotated computer keystoneyle (shown), but also the snapjack style which doesn’t require a punch down tool.  It’s called the keystone because it resembles an architectural element known as a keystone (see left).  It’s origin dates back to a 1979 patent by Amp inc. and a later patent by Int’l Connectors and Cable Corp. in 1995.  Technically the jack is the female connector installed in the wall plate, while the matching male connector is called the plug (even though it’s often referred to as the jack as well).  See also RJ and cable and connector photos.

CABLING NOTE:  You will note that there are two lines of colored squares on the above block for “punching down” the cable wires using a special punch down tool.  They are designated “A” and “B” and are called “pinouts,” based on the ANSI/EIA/TIA 568A and B networking standards (see Associations).  The same thing for the cabling of patch panels, both “A” and “B” schemes.  It doesn’t really matter which pinout series you use (at each end of the cable or component), so long as you are consistent throughout your network (see Tip#15), because the difference is that pairs 2 and 3 (orange and green pairs) are reversed, which could cause wiremap errors if not identically wired at each end of the cable.  Although the “A” wiring pattern is recognized to provide better backward compatibility for both both one and two pair AT&T USOC wiring, the U.S. Government and others require the use of the “B” standard, which is now the most widely used in the industry today, as it was adopted by N-TRON and matches the older AT&T color code and is approved by the ANSI/TIA/EIA standard as well.

PUNCTUATION MARKS: For interesting information about the derivation of such symbols as the at (“@”), tilde (“~”), pipe (“|”), carat (“^”), ampersand (“&”), bracket (“[ ]”), braces (“{  }”), parenthesis (“(  )”), angle brackets (“<  >”), octothorpe (“ # “) a/k/a pound or hashtag, asterisk (“ * “), virgule (“ /”) backslash (“ \ “), pilcrow (“ “), interpunct (“Interpunct “)section sign (“ §), bang* (!), interrobang (“ Interrobang copy “) [my personal favorite],  EM-Dash, EN-Dash (“---”) and other computer-related symbols, see those definitions within the  computer glossary.

[*I once read about a tech who used the password “I!littleboys”; it took quite some time for people to get it and become outraged.  The moral - know your punctuation marks.]

If you are interested in punctuation marks, you should know about Jean-Pierre Herve-Bazin, a French writer who, in his 1966 essay “Plumons l’Oiseau (“Let’s Pluck the Bird”) proposed six new punctuation marks:  Unlike even the Interrobang (above), these never became commonly available, although some graphics designer may offer them...


PUP:  Means “potentially unwanted program”.  Coined by anti-virus provider McAfee when software companies protested that their programs were classified as “spyware”.  McAfee distinguishes PUPs from spyware on the basis that spyware is always unwanted by the user, while PUPs may or may not actually be wanted, despite the fact that the user consented to the download. They rightfully claim that many computer users don’t really read each screen of their download agreement to provide sufficiently informed consent to those add-on programs which are automatically downloaded along with the program they actually want.  Most are harmless (like the “ASK Toolbar”) but many aren’t (like the Conduit Search Bar).

PUPPET:  One of the most popular cloud server-management software apps, it greatly reduces the number of steps and lots of necessary coding required to set up a server with the right software, storage space and network connections, particularly for cloud servers.  It is most useful in setting up and managing the tens or even hundreds of thousands of computers in cloud networks more easily.  It got the name because Luke Kanies, founder of Puppet Labs, decided it was like a puppet master, pulling on strings to give computers particular personalities and behaviors.  See also, Chef.

PUSH TECHNOLOGY:  Synonymous with “Webcasting” or sometimes “Netcasting.”  This is the prearranged periodic updating of data (i.e. news, weather, podcasts) to a computer desktop or an internet enabled cell phone screen over the Internet.  It’s called “push” technology because the Web server ostensibly “pushes” information to the user rather than waiting until the user specifically requests it.  This technology is included in Internet Explorer and many other programs (BackWeb, Castanet, Headliner, Pointcast, etc.)

PWN: Pronounced “own”.  A leetspeak verb meaning to “own” or dominate an opponent, as in “Bill pwns Jill in Halo”.  One widely accepted explanation for the term is that it grew out of a misspelling by a programmer in the World of WarCraft game, because the “o” and “p” keys are adjacent to each other on the keyboard

PWNIE: Pronounced “pony”. A device which is actually a minicomputer disguised as a power strip or internet router, which can be surreptitiously installed and go unnoticed in offices while intercepting network data, although it is also often used by white hat pen testers as well.  Often it is run on a Linux platform using powerful hacking software like Metasploit and the pwnie can be accessed from anywhere, pwning or “owning” the data it finds on the hacked network.

PXE-ROM:  Preboot Execution Environment.  This is an Intel legacy implementation, usually on computers containing an Intel PXE-ROM network card (“NIC”).  At boot, the program re-flashes the network card (NIC).  Newer cards retain the DHCP, don’t need to be re-flashed each time.  Can usually be disabled on newer machines.

Python_logoPython:  This is a general purpose programming language.  It’s design philosophy emphasizes programmer productivity and code readability.  This is an open, somewhat formally specified development model, initially released by Guido van Rossum in 1991.





























© Computer Coach.  All written materials are the sole property of Computer Coach (unless otherwise attributed) and no part of this website may be used in any format without the express written permission of Computer Coach.