“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.


Hedy Lamarr Wikipedia CommonsLAMARR, HEDY (b. Hedwig Eva Maria Kiesler, 1914 - 2000):  By now, thanks to the Internet, we now that many famous actresses of our generation have advanced degrees (Think: Mayin Bialik, PhD in neuroscience, Natalie Portman).  But even Old Hollywood glamour stars had their own advanced education.  Take Hedy Lamarr, a Vienna-born classic beauty and film star (with her very own star on the Hollywood Walk of Fame) who was mathematically gifted, educated and actually helped invent something important with her knowledge.  She learned a lot about weapons systems from her first husband, who was an Austrian munitions manufacturer.  She met George Antheil when she approached him at a dinner party and, familiar with his knowledge of endocrinology, asked him about the possibility of increasing the size of her breasts.  Antheil, a so-caled “avante garde” composer (who was also cross-educated, having written a book on endocrinology, columns giving advice to the lovelorn and articles about a variety of other subjects), proceeded to collaborate with Lamarr to develop and patent “spread spectrum technology,” which was created at that time to allow radio signals to torpedos to hop from frequency to frequency in order to avoid jamming by the enemy.  The Navy didn’t use it in 1942 (objecting to the size of the device), but 20 years later they did use the technology, during the Cuban Missile Crisis.  Thereafter it was resurrected by Sylvania and incorporated into virtually every Wi-Fi, satellite and broadcast technology and standard used today.  For more ready Richard Rhodes book “Hedy’s Folly”.  [Photo: Wikipedia Commons]

LAMP:  (Software Bundle) - This acronym refers to a common solution pack (called a “stack”) of software, usually free and open source, used to run dynamic websites or servers.  The original bundle included: Linux (O/S), Apache (web server), MySQL (database server) and PHP (programming language).  See also WISP, Microsoft’s version of LAMP.

LAN:  Local Access Network”.  This refers to a computer network (two or more computers connected together), cabled or wireless, in an area of restricted size, usually a home or office. See DIAGRAM.

LAND LINE:  Refers to POTS, plain old wired telephones.

LANDING PAGE:  The very first web page of a website that a user first accesses.

LANCZOS3 (or LANZOSH):  A “resampling” technique often used to resize digital images.  The resampling algorithm uses “multivariate interpolation” to achieve the resizing, which gives very high quality results, compared to the more commonly used and faster techniques such as linear or cubic interpolation, because it more closely approximates the optimal resampling “filter”.

LANTASTIC:  One of the early, now obsolete, PC networking products.

LAPTOP:  Originally a generic term for any self-contained battery/ac powered computer with a built-in LCD screen (monitor), laptops have evolved into many subcategories, usually depending on their size and capability.  For example: 1) a “full” laptop is generally about 7 lbs. or more in weight, 2” or so in thickness and has at least a 12” x 14” screen.  Usually it has a variety of ports and built-in CD/DVD/R-RW and floppy drives, rivaling the power and usability of a desktop computer.   [This discussion doesn’t count the “luggables” that preceded the laptop.  The very first was the Notetaker, designed by Alan Kay at Xerox; later, Osborne marketed a similar computer, which looked quite like a CPR machine.  Zenith also developed a rather heavy model, the Z-180, which looked more like today’s laptop. For a photo history, click HERE.]  Generally, the first laptop was considered to be the Grid Compass Model 1101, introduced in 1982, designed by British industrial designer Bill Moggridge in 1979. Now, nearly every computer manufacturer makes a laptop model, used by true road warriors.  2) A notebook laptop is generally slimmer in thickness (about an inch), lighter in weight (5 lbs or less) and sometimes without built-in drives (they may have to be added peripherally, using cables, if needed), but with a relatively full size screen.  3) The next smallest category of laptop is the sub-notebook or lightweight notebook, with an even smaller screen (11” diagonal), often requiring the use of a docking station to connect to external drives.  4) Tablet PCs are laptop computers (not the same as tablets, see #9 below) with a screen that doubles as a “slate” on which input can be made by writing or touching the keyboard on the screen, but are otherwise like most notebooks.  5) Mini-notebooks are laptop computers with screens ranging from 10 to 13 inches. 6) Ultra Mobile PCs (sometimes called MIDs, depending on their operating system; see UMPC, above) or netbooks (because their usefulness is generally limited to Internet and e-mail use) generally are the size of a paperback book, very light (due to SSDs, see above) with a 5 to 7 inch screen, relatively limited power and hard drive space, but still sporting a full keyboard and various external ports. 7) In 2011, Intel coined the term “ultrabook” to describe a new category of ultrathin laptop aimed to compete with both the emerging tablet market as well as Apple’s ultra-thin MacBook Air.  These fairly pricey ($1000 or so) laptops use Intel processors, have USB 3 and SSD drives and are often on standby boot.  8) Newest in laptop design is hardware called a Thin Client that looks like a netbook, but is designed to connect with a smartphone (via Bluetooth or USB cable) and share its operating system (e.g. Windows Mobile, Linux) and software applications.  These appeal to corporations because they can be much more tightly controlled by companies for security reasons, have no storage and are less expensive (example:  Redfly C8N).  9) Personal Digital Assistants (PDAs) and their successors, Internet Phones, a/k/a Smart Phones (Blackberry, iPhone, Android, etc.) are essentially more powerful telephones that can access the Internet in some fashion, as well as retrieve e-mail, but have limited visibility (due to the small screen) and data entry capabilities (due to touch screen or tiny, often compressed, keyboards) and almost never run desktop computer software (although they can store and create limited office documents using light programs like QuickOffice).  10) Blurring the line between these laptops is the more recent introduction of tablets, starting in 2009 with the Apple iPad, followed by copycats such as the Dell Streak, RIM Playbook, Entourage dual-screen and, most recently, the Microsoft Surface.  These tablets differ from the laptop computer tablets discussed in #4 above in that they are not attached to a computer, but instead are the computer, therefore they do not require an external mouse or keyboard to execute commands, and are generally slightly smaller (9-10 inch screen), much thinner and far lighter than a full laptop computer. They are generally offered in WiFi and 3G models, depending on the type of Internet connectivity desired.  However, they have more limited memory, processing power and speed and don’t have many of the features or full programs available on laptops.  And they’re smaller (but also thinner and lighter) than most laptops.  Many can’t be used as phones, although some of the newer ones have that capability.  And they can be either touch screen or traditional monitor.  For more about tablets, click HERE11) The introduction in 2013 of the Google Chromebook (mfd by Samsung and others) for about $249 created another choice for laptop users.  The Chromebook uses the Google Chrome operating system and is designed to operate primarily through the cloud, retrieving e-mail, surfing the net and using cloud programs like Google Docs for creating and storing text, audio and video files, although you can accomplish some work off-line.  12) Recently, we’ve also got phablets, which are basically smartphones with larger screens or tablets with expanded capabilities, still not as powerful as laptop computers, blurring the line between phones and tablets.  Also 13) laplets, a/k/a tabtops, usually hybrid tablets with a detachable keyboard, which are blurring the line between laptops and tablets, as tablets assume more of the productivity apps previously missing on the initial models.  Also called “2-in-1s,” they’re laptops that can function either as flat tablets or a standard clam-shell laptops with the attached keyboard (like the Microsoft Surface/Pro line of computers, the iPad Pro, Pixel-C and Galaxy TabPro S.  [By the way, predictions that tablets would replace laptops and even most desktops didn’t take place, as tablet sales slowed down, although the laplets are still moving along quite well.]  Got enough choices?   14) Then there are the mini-mobile computers, like the Raspberry Pi, but those are stretching the definition of laptop.  O.K., once you get your computer, click on the FAQs and Tips sections of this site for advice about batteries, getting it to last longer and the like.

General considerations in purchasing a laptop are (1) weight - the less the better, (2) screen size - 13 inches is excellent, 10 and 11.5 inches a little small, 15, 17 and 18 inches a little large and heavy, (3)  processor speed - any current processor is more than adequate, (4) battery life - if it matters, check the specs, some last quite long, others don’t, (5) mouse - pad, eraser, ball - check to see that you’re comfortable or else you’ll have to get an external one; and keyboard, what types of keys (standard or island) and layout are most comfortable for a user,(6) memory - get as much as you can, at least 4Gb, (7) storage - not as important, especially with cloud storage available virtually for free these days and flash or external drives - but enough to carry all the files you require, (8) graphics card - unless you’re doing graphic design, the one provided should be sufficient, (9) wireless - almost always built in these days, some even have built-in satellite access so you can connect everywhere (at a cost) many thinner laptops don’t have ethernet or telephone ports now (10) optical drives - hardly any have CD/DVDs these days, require an external drive (11) USBs - USB3 is increasingly available, a few have Firewire (if you need it), some have Thunderbolt; just make sure you have enough ports for your needs in a convenient location, as adding hubs doesn’t always work, as the signal can lose strength over the connecting cable. Same for other types of ports, e.g. if you need a port to read SD cards, make sure it has one, (12) MAC or PC - it’s your choice, both are similar in features and prices these days, and (13) price - $500 will get you an “acceptable” laptop, but if you have specific requirements, the price can easily ramp up to three to five  times that amount. (14) And with laptops it’s often a good idea to get the extended warranty that covers any type of accidental damage, unless this is short term purchase, as repair costs can be much higher than for a desktop. A standard one-year mfr warranty doesn’t cover abuse, so if you’re in a high risk environment (or have hyper kids), you might want this.  (15) Software could be a consideration - it used to be that computers came pre-loaded with MS Office or at least Works, but not now; it’s usually a trial version with a hefty purchase price once you’ve gotten used to it.   And make sure that, if you require software, you’re not losing out by getting only the cloud version (a la Chromebook) Click HERE for a discussion of the difference between a laptop and a Chromebook.  (16)  As with all other hardware purchases, make sure it comes with all necessary cables, batteries, straps, cases and the like.  (17) Some say that the case material is relevant, that the plastic cases hold the heat more than the metal ones, shortening the laptop life, but I haven’t seen any proof of this. (18) Finally, the proof is in the look and feel - test the laptop for the feel of the keyboard and mouse, the readability of the screen, and any other important features, making sure they personally suit you.

LATENCY:  Basically “delay”.  Or the time it takes to do something the computer requests. For example, referring to Internet transmission, this is the time between initiating a request for data and the beginning of the actual data transfer (a/k/a “throughput”).  The term is also used to explain the time required to seek data on HDDs or access RAM.

LAZYWEB:  Referring to the generic and lazy salutation from a blogger to its readers (“Dear...”) usually preceding a question they’re too lazy to research.

LAWS:  Computer laws have their own set of acronyms:  To see what CDA, DMCA, ECPA, SARBOX and the like stand for, and their effect on your business or your life, click HERE to go the LAWS page of this site.  Also, there are computing technology laws, like Moore’s Law, Godwin’s Law and Amdahl’s Law, and which are distributed throughout the site.

LBA:  Stands for Logical Block Addressing, a common scheme used for specifying the location (“addressing”) of blocks of data as stored on devices such as hard drives.  In this scheme, only one number is used to address the data, which is described in a single block.  Originally optional as a scheme in early IDE and SCSI drives, since 1996 most hard drives implement LBA, replacing the earlier CHS and ECHS (extended/cylinder head sector) schemes.

LC/MINI LC:  A type of cable connectors used for fibre optic networks - see connector photos.

LCD:  Short for Liquid Crystal Display, used on watches, TVs and computer monitors.  Developed in 1963 at RCA’s Sarnoff Research Center in Princeton, NJ, LCD displays use two sheets of polarizing material with a liquid crystal solution sandwiched between them.  When an electric current is passed through the liquid, the crystals align so that light cannot pass through them.  Each crystal is like a shutter, either allowing or blocking light.  Color LCD displays use two basic techniques for producing color: Passive-Matrix (including CSTN and DSTN technologies); and Active-Matrix (a/k/a thin-film transistor or “TFT”).  Most LCD screens used in laptop computers are backlight, or transmissive, to make them easier to read.  PLASMA technology is similar to LCD technology in that, instead of liquid crystal, the display contains an inert ionized gas between the panels to provide the image.  See SCREENS.  Also, LED, below.

LDAP: Lightweight Directory Access Protocol is an internet protocol (language) that e-mail and other programs use to look up information from the server.

LEAP: The product of a Florida start-up run by David Holz, using a small box and a USB connection, the Leap allows users to operate their computer using gestures with all ten fingers.  It’s based on a great improvement to the type of technology used by Kinect game boxes, but uses three tiny cameras to interpret hand gestures.  It is supposed to be available for sale on July 22, 2013.  And its only $79! You, too, can have a computer like the guys in CSI.

LEASE:  Generally applied to the length of time that a given IP address will be valid for a particular computer.  The length varies by how long the user is likely to require the internet connection at a particular location.  Using short leases, DHCP can dynamically reconfigure networks in which there are more computers than there are available IP addresses.

LED:  Short for Light Emitting Diode, used for electronics indicators and low voltage display lighting.  A diode is a semiconductor device (a solid electronic component that conducts electricity under specific conditions) that emits light when an electric current passes through it.  The light is not terribly bright and ranges in output from red to blue, but is highly efficient, long-lived and requires very low power.  See also, OLED (organic LED), which is a display technology based on the use of an organic substance, typically a polymer, as the semiconductor material in light-emitting diodes.  An OLED display is created by sandwiching organic thin films between two conductors.  When an electrical current is applied to this structure, it emits a bright light.  OLEDs don’t require backlighting, can be thinner and weigh less than other display technologies, and offer a wide viewing angle (up to 160 degrees) and use less power (only 2 - 10 volts), they are quite popular on TVs, laptops, and PDAs.  Newer OLED technology includes the FOLED (flexible organic LED), which is built into a portable, roll-up display.  The newest LEDs are being created using ultrathin inorganic LEDs which are brighter and more versatile (bendable; think human body or building displays).  See also LCD, above, and SCREENS.

LEED CERTIFICATION:  The Leadership in Energy and Environmental Design, Green Building Rating System, an ecology-oriented building certification program developed by the U.S. Green Building Council (“USGBC”).

LEETSPEAK:  Popular in the 1980s, “1337speak,” read as “leetspeak,”  was a corrupt style of the English language marked by liberal interchanging of numbers and symbols in place of certain letters that arose from the so-called “leet” (i.e. “elite”) subculture of hackers in the late 1980s and later, gamers in the 1990s.  Now considered an outdated vernacular, 1337speak established a way to “be cool” on the Internet and left many other lasting legacies in the online gaming world -- most notably “n00bs” (“newbies”) and “getting pwned” (“owned”).  Click HERE for the universal Leetspeak translator/generator.

LEGACY:  Old.  Applies to software or hardware that predates the current version of a program or device.  For example, Windows 98 and XP are legacy software to the current Windows Vista.  Tape drives and 5.25” floppy disk drives would be legacy hardware.  Opposite of nascent (new).

LEGACY FOOTPRINT:  Remnants of your digital identity and searches on Internet that remain after your searches, i.e. a sort “digital exhaust” that can be traced by hackers after you’ve moved on.

LEGEND TRIPPING:  The practice of visiting a site where some horrific, supernatural or haunting event allegedly took place (like the TV series Ghost Hunters).  Sometimes it’s a right of passage, as in those horror movies where students take a dare to stay overnight in a haunted house.  Sometimes, the events take place in order to further a fictitious entity (like Slenderman).   The practice is derived from as far back as Mark Twain’s Tom Sawyer which contains several accounts of Tom Sawyer, Huckleberry Finn and Becky Thatcher visiting allegedly haunted houses and caves.  The legend tripping goes back even further in England and other countries.   The Internet has only exacerbated this practice.       

LEHMER SIEVE:  A primitive digital computer usingLehmer sieve tapes used for finding prime numbers and solving simple Diophantine equations.  The Babbage Analytical Engine automated this work.

LETTERBOXING:  Also called “LBX,” this is “widesceen” where movies and videos are displayed in the same aspect ratio that they are filmed, often leaving a black line above and below, but preserving the entire viewing area.

lexmarkLEXMARK:  A Lexington, KY company that is primarily in the business of  manufacturing computer printers.  In August, 2012 it made the decision to exit the inkjet printer business, but it still manufactures and sells laser printers.  The company was formed on March 27, 1991 when IBM divested itself some of its hardware businesses, and in 1995 it became a publicly traded company on the NYSE.  The name Lexmark is a portmanteau of “lexicon” and “Mark”.

LIAM:  Apple’s 29 arm robot designed to take iPhones apart in precisely 11 seconds.  (The name doesn’t stand for anything in particular.)  It’s located in Apple’s headquarters in Cupertino, CA.

LIBRARY:  (1) A type of file folder introduced in Windows 7.  It is a special-purpose virtual folder.  A library folder gathers files that are stored in several locations (including multiple computers) and monitors (but doesn’t copy) them in a single place. This can make searching particularly powerful.  For more information about how it is intended to work, click HERE(2) Also a repository of files of a specific type used in coding, as in a library for Python or Ruby code development, so that code blocks don’t have to be re-invented.

J C R LICKLIDER PHOTOLICKLIDER, J.C.R:  1915 - 1990. One of the “Founding Fathers of the Internet”.  He was a psychologist at MIT who outlined his dream of a “Galactic Network” in the 1960s and later, while at DARPA, pretty much described today’s Internet.  “Lick” carried the torch in the late 1960s at DARPA, building ARPAnet with the help of many others, starting with Lawrence G. Roberts (see his bio for more) moving from the concept to the reality of the Internet.

LiFi:  Wi-Fi connectivity through a LED light bulb.  Chi Nan, an IT professor at Shanghai’s Fudan University, claimed in 2013 that a one watt LED light bulb could provide internet connectivity up to 150Mbps for four computers.  This process was confirmed by Harald Haas of the University of Edinburgh in 2011, who actually coined the term “Li-Fi”.  Also known as “visible light communications (“VLC”), a microchipped LED bulb could produce a connection cheaper (by using less electricity) and faster than the average broadband connection, because visible light is part of the electromagnetic spectrum and 10,000 greater than the radio spectrum, affording potentially unlimited capacity.  On the down side, if you block the light, the signal connection will be lost.  But, on the up side, aside from the cost savings, it’s hard to hack a light that can’t pass through walls, so there’s security from hackers.  And the use of hundreds of LEDs to create billboards and indoor lights means that you won’t have to use just one bulb.  For example, the Fraunhofer Heinrich Hertz Institute claimed that it could achieve 3Gbits/s per LED by making a bulb with three colors.  Obviously, this technology is still in its infancy, but it could eventually be a game changer.

LIFX:  A LED light bulb (much like the Philips Hue) that can be controlled from a phone app, without the need for a router.  See also, IoT.

Lightning:  Apple’s name for the smaller, redesigned 9 pin dock connector introduced in 2012 with the iPhone 5, replacing the old larger 30 pin connector.  Apple gave it this name because it was supposed to be so much faster.  For facts about weather lightning, click HERE.

LightRadio:  A technology developed by Alcatel-Lucent using a lightweight module (about 2.5” square, 10.5ozs) which can be placed on roofs, bus stops, etc. and which can replace huge, bulky cell phone towers for transmitting cell signals.  See also, femtocells.

Lightscribe logoLightScribe:  A technology developed by Hewlett-Packard that enables direct burning of text and graphics labels onto specially coated CD and DVD “LightScribe” disks which chemically change when the disk drive’s laser strikes the label side of the disk. Requires a special lightscribe drive to do this. 

Lights Out: Refers to a climate-controlled computer or server room with extremely limited access (therefore using fewer lights).  There is some dispute about whether this type of server room, having few personnel, is advantageous.

Facebook Like logoLIKE:  Introduced in 2010, a button placed on a Facebook or other web page that userNEW facebook like logos click to show on Facebook that they like the page.  Initially shown as a thumbs-up logo, in late 2013 Facebook modified it to an “f” to show better on high resolution screens (they said). (It’s said an Israeli couple named their child “Like” after this feature.  But that was reported on Wikipedia, so it may or may not be correct.)

LIMEWIRE: A popular open source peer-to-peer client software package for file sharing.  Founded in 2000 by Mark Gorton, a successful Wall Street trader. Also supports Gunnel and BitTorrent file sharing networks.  In October, 2010, a NY Federal judge ordered the service to close its download links, essentially shutting down the site, following in the steps of its predecessors Napster, Morpheus and Grokster, all of which lost legal battles with the music industry, specifically the RIAA.

LINEAR THINKING:  Any process that is linear involves the organization of ideas in a step-by-step process along a straight line from definition to solution.  Linear thinking is very structured and result oriented.  As a result, quite often ideas “outside the box” are discarded in the process.  In such cases, “Radiant” thinking, the opposite of Linear thinking is more useful, as it is a more “free form” process, like “brainstorming,” where all ideas are gathered, the later discarded, whether or not they may actually be useful.

LinguoLINGUO: A grammar-correcting robot created by Homer Simpson’s daughter Lisa for the Springfield Science Fair.  Homer nearly destroys it when he gives it beer.  It is also the name of a phone translation program for iPhones, but is no longer in the app store.

linked in logoLINKEDIN:  A social networking site primarilyReid_Hoffman aimed at business networking, founded by Reid Hoffman of PayPal (photo) and Jeff Weiner of Yahoo! in May 2003. Filed for an IPO in 1/2011 and traded first shares on 5/19/11.  In mid-2016, Microsoft purchased Linkedin for $26 billion, primarily an effort to collect and integrate data (Outlook calendar an meetings, co-worker info from Delve, Microsoft accounts (Dynamics CRM) and merge its Office365 apps with Cortana into an interrelational “Office Graph”.

LINPACK BENCHMARK: Created in the 1970s by Jack Dongarra, a metric used to measure supercomputer performance by solving a dense system of linear equations.

LIQUID WORKFLOW: The computing environment where there is no primary computer device, but all devices are seamlessly connected through the cloud.

LIQUIDMETAL:  A class of patented amorphous metal alloys (basically metallic glass) which has unique properties such as high strength, excellent wear resistance against scratching and denting and good strength to weight to ratio. As opposed to the bending or die-casting with an inferior alloy (aluminum, magnesium) required to shape metal, the liquidmetal can be injection molded and still have similar properties to metal.  Discovered at the California Institute of Technology in 1992, Apple was granted right to use it in August, 2010, and is expected to use it on the latest generation of iPhones in 2012.

LINUX:  A free open-source operating system originally developed in 1991 by Linus Torvalds as an alternative to Windows and other closed-source operating systems.  Currently developed by a world wide team of volunteer programmers and sold by several large software companies (e.g. Red Hat, Sun) called distros.  Can be freely downloaded and modified.  Mascot: “Tux” the penguin. For more, see LINUX.

LISA: The first personal computer designed by Apple during the early 1980s.  The thought was to design a more powerful computer which would target business customers.  It was one of Apple’s few failures.  Businesses balked at the high price and limited software and opted instead to run the less expensive IBM PCs, which were introduced about the same time.  The two subsequent models, the Lisa 2 and the Macintosh XL didn’t fare much better, and the line was abandoned in 1986, to be replaced by the much more popular and adaptable Macintosh.  Apple stated that the name Lisa was an acronym meaning “Local Integrated Software Architecture” but, since Steve Jobs’ first daughter was born in 1978 and named Lisa, there is some conjecture that the name also had a personal association and that the acronym was actually invented to fit the name (See Glossary, “bacronym”.)

Lisp_logoLISP: A open source programming language invented by John McCarthy McCarthy, John 2in 1960 while he was at MIT.  It went on to become the programming language of choice for the artificial intelligence community. LISP was different at the time because it used symbolic expressions rather than numbers, giving AI researchers the ability to be more creative.  He was also credited with coining the term “Artificial Intelligence”. He died in October, 2011 at the age of 84. Clojure, created by Rich Hickey, is an updated version of Lisp which works well when compiled with Java.

LIVE PHOTO:  A feature introduced with iPhone 6, which shows a short video when one long-holds what appears to be a photo on the phone.

LIVESCRIBE: A technology which uses a pen and special notepaperLivescribe pen, used by students and others to take notes in classes and meetings.  The original pen worked like this:  When you tap on a word or sentence, the pen will replay a recording of what was being said or taking place at the exact instant that the words were handwritten on the paper. The most recent version, the (rather large) Smartpen 3 ($149), takes the notes on special paper, then transfers the digital version for storage in several places for retrieval or sharing with team members or groups.  While it uses an app installed with iPhone or iPad, it syncs with Microsoft’s OneNote software, although it’s not a seamless process.  And the notes are a digital copy of the handwritten notes, not typed text (as with smarphones like the Samsung Galaxy Note 3), so they can’t be edited; they’re more like a scan with no OCR.  See, Also, OneNote, Evernote and Google Keep for a discussion of the software that can be used with these pens. 

LIVESTREAM ON FACEBOOK: The ability to post live streaming video on Facebook.  Competes with Google’s Periscope and others.

LLTD: Link-Layer Topology Discovery Responder to WinXP.  This is a free utility from Microsoft that makes XP networking easier and more reliable.  It can be downloaded HERE and, for XP SP3 HERE.

LOAD BALANCING:  A method of making a computer network more efficient, by distributing processes and traffic evenly across the network, making sure that no single or group of devices is overwhelmed.

LOCALTALK: See, AppleTalk.

LOCKER SERVICE:   A service, usually a cloud service, which provides access to automated backup copies of previously purchased software or songs if the originals are damaged or lost.   Apple and Google offer locker services.  The opposite of a locker service is a Chop Shop, where parties who don’t know each other share copies of music for which they have not paid.  In short, a site to distribute illegal copies of music for profit.

LOG: As relating to computers, this is pretty much the same definition as with other disciplines, a record of events for a specified period of time, like the Windows Event Error Log.  See also, blog.

LOGIC BOMB (a/k/a slag code): A set of instructions secretly incorporated into a program which lies dormant and is designed to explode (i.e. execute) after a specified period of time (a latency period) for malicious purposes such as erasing or corrupting data, reformatting a drive or releasing a malware payload.

LOGIC GATE: One of the most elementary building blocks of digital circuit design.  It is called a “logic” gate because, at any given moment, it is in either of two (“binary”) conditions - low or high (generally representing voltage levels). That is, it performs a logical operation, using logic circuits such as computer memory or arithmetic logic units (“ALUs”) on it’s inputs to produce a single logical output, implementing the logic circuits using various electronic components like transistors, which can, for example, shut power on or off. In any given circuit, there are seven basic types of logic gates:  AND, OR, XOR, NOT, NAND, NOR and XNOR.  Most logic gates have two inputs and a single output.  The AND gate is named  a logic gate because if “0” is “false” and “1” is “true” the gate acts in the same way as the logical “and" operator.  This can be quite complex (for example, in reversible logic, Toffoli gates are used!  And in quantum computing, Fredkin gates suitable for reversible computing, see quantum computing for more). For application purposes, see Quantum computing and Qubit. And click HERE for more about how logic gates are used in programming.

LOOP: Hardware - (1) Any circuit which theoretically begins and ends at a certain point.  Also, (2) in telephone lingo, a local loop, which is  the wired connection from the telco’s local central office to the demarc at each customer’s home or business.  See demarc, NID, loopback (below).

LOOPBACK: Software - A test signal sent back to the telephone company as the originator of the signal, showing that has been received at the destination.  This test is used to verify connections and diagnose problems.  Often the test on telephone lines is performed using a special plug called a “wrap plug” which returns transmitted data to be returned when it is inserted into a port on the communications device, thus simulating a complete communication circuit.  Comparable to the ping utility which is used to verify the connection between a host and another computer on the Internet.

LOSSY:  A term used to describe the “loss” of quality when a .jpg image is edited and saved repeatedly.  This is because when it is saved, .jpg artifacts are added so that the colors become less accurate each time.

Lotus_1-2-3_9.8_iconLOTUS:  An integrated spreadsheet, database manager and graphics program developed by Mitch Kapor (formerly of Visicalc Corp) and Jonathan Sachs (in the name Lotus Development Corp.) in 1982 which, because of the triple integration, became known as Lotus 1-2-3.  It’s importance was that at the time of its introduction there was no graphic user interface (“GUI”) on the early IBM PCs, so Lotus’ useful and easy-to-use WISIWIG format greatly furthered the use of these tools.  Eventually Lotus brought in other products, such as Organizer, AmiPro (word processor) and Notes Lotus_software logo(groupware and e-mail) and became known as Lotus Smart Suite.  The whole company was acquired by and integrated into IBM in 1995. 

ADA Lovelace2LOVELACE, ADA:  Generally considered to be the very first computer programmer.  In the mid-19th century, she decided to study mathematics in order to discipline her artistic mind.   She had a working and stormy personal relationship with with mathematician Charles Babbage, who was at that time a notable professor of mathematics at the University of Cambridge in England.  Babbage invented what he called the Analytical Engine, a complex calculating precursor to the computer.  Inspired by Jacquard looms popular at the time and fashioned from big brass wheels, the huge machine (see Babbage definition for photo) was capable of computing prime numbers, and bernoulli numbers (improving on the Lehmer sieve) and solving equations.  After Lovelace translated a piece written by mathematician Luigi Menabrae about the Analytical Engine, and added some of her own programs, she served as Babbage’s key public interpreter.   It was Lovelace who suggested programming the machine with punch cards, vastly increasing its versatility. As opposed to Babbage, who only viewed the machine’s capabilities to work with large tables of numbers, with her artistic bent, she viewed the use of the Engine to create music or even art.  She wrote and published the world’s first program for the machine in 1843, many more after that.   But the Engine was apparently ahead of its time and never used.  She died at age 36 of cancer.  In the ‘70s, the U.S. DoD named a computer language (“ADA”) after her.  Interestingly, she was born in 1815 as Ada Gordon. and her father was poet Lord Byron; her mother was Annabella Milbanks. She married William King, an aristocrat who later became the Earl of Lovelace, making Ada the Countess of Lovelace.  Ada Lovelace Day (October 14th) was started in 2009 by Suw Charman-Anderson, who asks those to celebrate Lovelace’s memory by asking people to blog about women that they admire in the fields of science, technology, engineering or math. 

LOVELACE TEST:  Like the Turing Test, the Lovelace Test is a test of a computer’s ability to be equal to or indistinguishable from that of a human.  The test was not designed by Ada Lovelace, but by a team led by Selmer Bringsjord (the same team that developed the IBM Watson computer) in the early 2000s and named after Lovelace.  Some claim that the Lovelace test is more accurate, as it can’t be manipulated as easily as the Turing “captcha” tests, because it doesn’t rely simply on syntax but instead on genuine autonomous intelligence (human-like creativity and origination).  A computer passes the Lovelace test only if it originates a new program (an idea, a novel, a piece of music - remember Ada’s arts background) that can’t be a hardware hack.  To pass the test, then, a computer must create something original, all by itself.

LPD and LPD/LPR:  Line Printer Daemon/Line Printer Remote protocol.  Sometimes referred to as TCP/IP printer.  The most common printer application used to connect a network printer.  It listens on Port 515.  Note that the LPD cue name is case sensitive.  See printers, also IPP.

LSO:  Local Shared Objects”.  An object similar to a third party cookie which is loaded onto computers to view Flash presentations.  See, COOKIES.

LTE:  Long Term Evolution (of Universal Terrestrial Radio Access Network)”.  Generically, this refers to, along with WiMax, to the evolution of 4G mobile technology that will deliver users the benefits of faster data speeds and new services, by creating a new radio access technology that is optimized for IP-based traffic.  In some sense this is a cellular competitor to WIMAX.  See WIMAX.

lte-u logoLTE-U:  The proposed use by carriers like Verizon and T-Mobile to use the “unlicensed” spectrums like 5Ghz to speed up smart phone transmissions in congested areas, in addition to those spectrums already specifically “licensed” by the FCC for cellular use. This standard of coexistence is still being developed by Qualcomm and its partners, but has met some resistance because of possible interference with existing nearby hotspots which could slow down or block some existing Wi-Fi connections.  Even if hardware devices can separate the connections across different channels through DFS (“Dynamic Frequency Selection”), the increased congestion alone could still be a serious problem. Two radio waves in the same spectrum at the same time simply increases interference.

LUDDITE:  A descriptive word not necessarily limited to computers, but frequently applied to them, this refers to someone who is generally opposed to new technology.  Literally, someone who literally “smashes” computers.  It is derived from a group of 19th century English workmen who between 1811 and 1817 destroyed labor-saving machinery like power looms and spinning and stocking frames for weaving textiles developed at that time in protest of change to the old manual way of doing things.  The newer technology threatened to replace the jobs of lower wage and less skilled artisans. 

The name Luddite is believed to come from the name Ned Ludd (or, possibly, Ned Lud, Ned Ludlam or Edward Ludlam), a kind of Robin Hood character, who allegedly destroyed some loom machinery in 1779, not in protest of anything other than his own situation.  Later his name was used in a Luddfolkloric manner (General or Captain or King Lud) by organized knitting frame breakers who were protesting the advance in weaving technology which would put workers out of their jobs.  Since it was too early for cameras, only an engraving in the Smithsonian depicts what Ludd looked like (see right)> 

LUHN (ALGORITHM or FORMULA), a/k/a/ “MOD 10”:  A checksum formula used to validate a variety of identification numbers, LUHN PHOTOincluding credit card, insurance and IMEI numbers. It has become known as ISO/IEC 7812 (see Associations).  It was created by IBM scientist Hans Peter Luhn and patented on August 23, 1960.  While it is a security measure, it is only used to verify the correct entry of ID numbers, but it is not intended to be as secure as a cryptographic hash function.

LVDS:  Low Voltage Differential Signaling.  Introduced into computers in the 1990s, it is a high speed digital interface used for applications that require high noise immunity and low power consumption for high data rates, such as those required by commercial and military applications.  LVDS comes in several sizes and types, depending on the application.  LVDS are used with 100 ohm flat flexible cables terminated with connectors compatible with FI-R connections.  See connectors.

LyftLYFT:  An app-dispatched ride sharing company, founded by John Zimmer and Logan Green in 2012 in San Francisco (like Uber), which uses private drivers with their own cars to effecLyfttively serve as cabs at a lower rate.  The two founders created Lyft as an outgrowth of Zimride, a ridesharing service founded in 2007.  Distinguished by the fuzzy pink mustaches on the front of their cars.  It is one of several TNC (Transportation Network Companies) such as Uber (the largest) and Sidecar (in Seattle, WA).  Popularized (without compensation) by Conan, Ice Cube and Kevin Hart.  Since cab companies pay tons of money for their medallions, it’s hard to believe that they won’t seriously fight back if this becomes mainstream.  In 2015 GM invested $500 million in Lyft.  See TN for more.

Lync logoLYNC:  A Microsoft program which supports audio and visual conferencing with shared whiteboard and documents. It’s internet telephony, doesn’t use standard phone lines.  It also can delve into Outlook 2010 on users’ machines and tell you whether they are on line and available to take your call.





























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