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The Simplest Possible Tutorial...
Glossary of Computer Terms

This glossary is by no means complete, nor should you expect to learn all of the terms and acronyms. I will be pleased to add any that have been omitted or newly generated, providing that they add information rather than clutter to what really is a beginner's guide. Should you require more information on any topic then please highlight the term and copy and past it into the search facility at right.

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Clicking on any of the letters in the alphabet that are in the boxes with the red outline will return you to the place that you have just come from. If the word that you are looking at is highlighted then, clicking on it will take you directly to a sub page describing the topic.


#   Is used here in the American sense and refers to numbers or symbols.
.   Decimal point, but known as 'dot' in computing terms.
:=   Becomes or 'Becomes equal to'.
~   Tilde (pronounced 'tilda') also occasionally called Attila.
_   Underscore or Underline.
/   Forward slash, sometimes just 'slash' or stroke (from 'shilling stroke').
\   Backslash.
*   Wildcard character - asterisk or star.
*.*   Star Dot Star - represents any filename.any filename extension.
.$$$   Temporary File - filename extension particularly automatically generated 'back-up' files.
...   More follows.


ACE... Automatic Computing Engine.
Acronym... A set of alphabetic characters (often initials) that are a shorthand version of a phrase.
ADA... Programming Language named after Augusta Ada Lovelace.
ADL... Address Data Latch.
ADN... Advanced Digital Network.. Often refers to a 56 Kbps leased-line.
ADR... Address.
ADSL... Asymmetric Digital Subscriber Line.
AFIS... Automatic Fingerprint Identification System.
AGC... Automatic Gain Control (developed by Armand Dennis).
AGP... Accelerated or Advanced Graphics Port.
ALGOL... Algorithmic Oriented Language.
ALINK... Active Link in HTML BODY tag.
ALT... Alternate.
ALU... Arithmetic Logic Unit.
Anonymous FTP... File Transfer Protocol that does not require a password.
Applet... A small section of Java code that can be used within an HTML page.
Application... A programmed set of instructions that can perform a specific task, word processing, spreadsheet, drawing an icon etc.
Archie... An early software tool for finding files stored on anonymous FTP sites.
ARM... Advanced RISC Machine.
ARPANET... Advanced Research Projects Agency Network) - an experiment in wide area networking that led to the internet that we know today.
ASCII... American Standard Code for Information Interchange.
ATAPI... Advanced Technology Attachment Packet Interface.
ATM... Asynchronous Transfer Mode.
ATOZ... "A" to "Z", or Alphabetic Index.
ATX... Advanced Technology Extended.


B2B... Business-To-Business.
.BAK or. bak file name extension for backup files.
BALUN... Balanced Unbalanced.
Bandwidth... maximum transmission rate, measured in bits per second or Mb/sec.
BASIC... Beginner's All-purpose Symbolic Instruction Code.
Baud rate... refers to the number of distinct events per second in a modulated signal.
BBS... Bulletin Board System.
BCC: .. Blind Carbon Copy.
BCD... Binary Coded Decimal.
BGA... Ball Grid Array.
BGCOLOR... Background Colour in HTML table and body tags.
.BIN or .bin... file name extension for binary files.
Binary... a counting system consisting of ones and zeros (on or off states).
Binhex... BINary to HEXadecimal conversion.
BIOS... Basic Input/Output System.
Bit... Binary DigIT.
BITNET... Because It's There NETwork - a separate Email system within the internet.
Blog... a contraction of weB LOG.
.BMP or .bmp... file name extension for bitmap format image files.
bps... bits per second.
Browser... An application that can lay out data from files or the internet for viewing on a screen.
BTW... Email acronym for 'By The Way'.
Byte... 8 Bits that represent a single (usually ASCII) character.


C... A Programming Language.
CAD... Computer Aided Design.
CAM... Computer Aided Manufacturing.
CASE... Computer Aided Software Engineering.
CAT SCAN... Computerised Axial Tomography Scan.
Certificate Authority... The issuer of security certificates.
CGI... Common Gateway Interface.
CGI-BIN... Common Gateway Interface - BINary. In lower case - a commonly used name for the directory or folder on a web server in which CGI programs are stored.
CHAT... Conversational Hypertext Access Technology.
CIX... Compulink Information Exchange.
Client... A software application that is used to obtain data from a server or another computer.
CLK... Clock (usually the system clock, not time of day).
CMOS... Complementary Metal Oxide Semiconductor, in computer usage often refers to just a small amount of memory that is battery backed and contains BIOS settings.
CMY... Cyan Magenta Yellow (3 colour).
CMYK... Cyan Magenta Yellow Black (4 Colour).
COAX... Coaxial Cable.
COBOL... Common Business oriented Language.
.COM or .com... file name extension of a command file. Often used to indicate a business that is internet based.
COM1... First serial Port - also COM2 = Second serial Port, COM3 = Third, COM4 = Fourth and so on.
CONFIG... Configure or Configuration.
Cookie... Internet Cookies are a packet of information sent by a web server that the browser is expected to lodge on the machine and send back to the server whenever the browser makes an additional future request from the same server.
CP/M... Control Program for Microcomputers developed by Digital Research.
CRT... Cathode Ray Tube.
CSS... Cascading Style Sheet, coding that specifies the appearance of text and other elements.
CUP... Cursor Position.
Cyberspace... The ethereal space that is deemed to be occupied by computers and data.
CYL... Cylinder.


D/A... Digital to Analog.
DAB... Digital Audio Broadcasting.
DAC... Digital to Analog Converter (also my initials which are found many times on this website).
DAT... Digital Audio Tape or Disk Array Technology.
.DAT or .dat... file name extension for data files.
Data... Information in the form of numbers or code that a computer can work with.
dB... Decibel.
DEFRAG... De fragment.
DEK... Data Encryption Key.
DEL... Delete.
DIMM... Dual In Line Memory Module.
DNS... Domain Name System, translates Internet domain names into IP numbers.
DNS Server... Is a server that performs this kind of translation.
DMA... Direct Memory Access.
.DOC or .doc... file name extension for a document file (largely usurped by Microsoft for 'Word' format files).
Domain Name... A unique name that identifies an Internet site. Domain Names always have 2 or more parts, separated by dots.
Download... Transferring a file (or files) from a remote computer to the one you are using.
DRAM... Dynamic Random Access Memory.
DSL... Digital Subscriber Line.
DVD... Digital Video Disk.


EAROM... Electrically Alterable Read Only Memory.
EEPROM... Electrically Erasable Programmable Read Only Memory.
EGA... Enhanced Graphics Adapter.
EIDE... Enhanced Integrated Drive Electronics.
Email... Electronic Mail.
EMC... Electromagnetic Compatibility.
EOF... End Of File.
EOL... End Of Line.
EROM... Erasable Read Only Memory.
ESC... Escape.
ESDRAM... Enhanced SDRAM.
Ethernet... A popular method of coupling computers together in a LAN.
.EXE or .exe... file name extension for an executable file.
Extranet... An intranet that is accessible to computers other than those particularly on the main site. (like car dealers linked to a car manufacturer).
E-ZINE... Electronic Magazine.


FAT... (File Allocation Table) FAT32, FAT16, FAT12 are file organising systems for hard disks running under the 'Chicago' platform.
FAQ... (Frequently Asked Questions) a document that lists and answers the most common questions on a particular topic.
FAX... Facsimile.
FCC: .. File Carbon Copy.
FDDI... Fibre Distribution Data Interface - uses fibre optics instead of wire for signal transmission between computers.
FDISK... Fixed Disk.
FERAM... Ferroelectric RAM.
FET... Field Effect Transistor.
FF... Form Feed.
FIFO... First In, First Out.
FILO... First In, Last Out.
FINDSTR... Find Strings.
Finger... An Internet application for locating people on other Internet sites.
Fire Wall... Hardware and/or software that separates a Network into 'safe' and 'unsafe' areas.
Flame... Derogatory or insulting comments or the act of making them.
Flame War... Heated personal attacks among debaters in a fierce argument.
FLOPS... Floating Point Operations Per Second.
FORTH... A threaded list programming language.
FORTRAN... Formula Translator programming Language.
FPS... Frames Per Second.
FSB... Front Side Bus.
FSK... Frequency Shift Keying.
FST... Flat Square Tube or Flatter Squarer Tube (CRT - Cathode Ray Tube).
FTP... File Transfer Protocol, for moving files between two Internet sites.
FYI... For Your Information.


Gateway... A term for a hardware or software interface that translates between two dissimilar protocols.
GIF... Graphic Interchange Format, for image files that have large areas of single colours.
Gigabyte... 1024 Megabytes, but sometimes only 1000 Megabytes.
GIGO... Garbage In := Garbage Out.
GIMP... GNU Image Manipulation Program.
GND... Ground. earth or common in an electrical circuit.
GNOME... GNU Network Object Model Environment.
GOOGLE... A very good (to my mind the best) search engine. The Meaning of the word 'Google' is a play on the word googol, which was coined by Milton Sirotta, nephew of American mathematician Edward Kasner, to refer to the number represented by 1 followed by 100 zeros. Google's use of the term reflects the company's mission to organize the immense amount of information available on the web.
Gopher... An early form of information dissemination and retrieval that has been supplanted by hypertext.
GPS... Global Positioning System (service).
GUI... Graphical User Interface.


Hardware... A collection of mechanical and electrical bits and pieces forming the physical components and structure of a computer.
HD... Hard Disk or High Density.
HDD... Hard Disk Drive.
HEX... Hexadecimal (base 16).
HGA... Hercules Graphics Adapter.
HIMEM... High Memory.
Hit... A visitor to a web page, originally a request by a browser for an item from a web server.
Home Page... sometimes spelt as all one word (homepage)... Originally, the web page that your browser is set to use at start up. A more recent meaning refers to the main web page for website or group of web pages.
Host... A computer on a network that is a repository for Email or Internet services for other computers to access.
HPGL... Hewlett-Packard Graphics Language.
HTML... HyperText Markup Language, HTML is a very simple markup language based on the more comprehensive SGML.
HTTP... HyperText Transfer Protocol, the main means of file transport on the internet.
Hypertext... Text that contains links to other documents or other parts of the same document.
Hz... Hertz, frequency of a periodic waveform.


IAL... International Algebraic Language, (ALGOL was originally called IAL).
IDE... Integrated Drive Electronics or Intelligent Drive Electronics.
IMAP... Internet Message Access Protocol.
IMHO... Acronym for 'In My Humble Opinion' (often used with tongue in cheek).
.INI or .ini... file name extension for initializing files
Internet... The web of interconnected networks that are connected using TCP/IP protocol, that evolved from the original ARPANET.
Intranet... A private network within a company or building that uses the same protocols as the internet.
IP Number... Internet Protocol Number (dotted quad) a unique number consisting of 4 parts separated by dots, that determines a unique address under TCP/IP.
IR... Infrared.
IRC... Internet Relay Chat - a multi user live chat or conference facility.
IRQ... Interrupt Request.
ISA... Industry Standard Architecture.
ISDN... Integrated Services Digital Network provides speeds of about 128,000 bits per second over conventional phone lines.
ISP... Internet Service Provider. A company that provides access to the Internet.


Java... is a programming language developed by Sun Microsystems.
JavaScript... Minor programming that can be incorporated within HTML to automate some actions.
JDK... Java Development Kit (a software development pack from Sun Microsystems).
JEDEC... Joint Electronic Devices Engineering Council.
JPEG... Joint Photographic Experts Group, an image format for detailed images or photographs.
JVM... Java Virtual Machine.


KHz... Kilohertz.
Kilobyte... 1,024 (210) bytes, occasionally only 1,000 bytes in 'cheapskate' systems.


LAN... Local Area Network is a network of limited area and scope, usually the same building or floor of a building or possibly a group of buildings.
LCD... Liquid Crystal Display.
Leased Line... A telephone line or fibre optic cable that is rented for your network or companies.
LIFO... Last In, First Out.
LILO... Last In, Last Out.
LINUX... A widely used 'Open Source' operating system that is growing in popularity, based on UNIX.
LISP... List Processing language.
Listserv ®... A type of Email list or forum, "Listserv" is a registered trademark of L-Soft international, Inc.
Login... As a noun, the user name required to access a computer system.
As a verb, the act of connecting to a computer system by giving 'username' and 'password'.
LOGO... A programming Language.
LPT1... First Parallel Printer Port, similarly LPT2 = Second Parallel Printer Port and so on.


mA... Milliampere.
MAC... Macintosh (Apple Macintosh Computer).
mAh... Milliampere-Hour.
Maillist... Mail list or Mailing List, a discussion group system that allows people to send Email to one address for onward transmission to a group of other Email addresses.
MAPI... Mail or Messaging Applications Programming.
MBR... Master Boot Record.
MCA... Micro Channel Adapter or Architecture.
Megabyte... 1,024 kilobytes, 1,048,576 bytes or a million bytes in cheapskate systems.
MEM... Memory.
Meta Tag... A type of HTML tag that contains information not normally displayed to the user, but describing the page itself and it's originator.
MFT... (Master File Table), which contains information about all the files and folders on an NTFS volume.
MICRO... One millionth part of.
MIDI... Musical Instrument Digital Interface.
MIME... Multipurpose Internet Mail Extensions, originally a standard for defining the types of files attached to standard Email messages. The MIME standard has come to mean information about what kind of file is being sent by any transmission method.
Mirror... To maintain an exact copy of a file or hard drive contents.
Mirror Site... A web site, or FTP site that maintains duplicate copies of material originated at another location.
MISC... Miscellaneous.
MOBO... Mother Board.
Modem... Modulator, DEModulator - a unit that connects a computer to a telephone line and transmits (and receives) data as a series of sound pulses.
Monitor... A TV like device or flat screen that displays text or graphics.
MOSFET... Metal Oxide Semiconductor Field Effect Transistor.
MP3... MPEG Audio Layer 3.
MPEG... Moving Picture Experts Group.
MSG... Message\par MSIMN... Microsoft Internet Mail and News.
MTBF... Mean Time Before Failure.
mV... Millivolt.


NAND... Not And logical operator.
NANO... One thousand millionth part of.
Netiquette... The etiquette standards used on the Internet.
Netscape... A browser as well as the name of a company.
Network... As a verb - To connect 2 or more computers together in order to share resources. As a noun - The actual group of connected computers, their connecting cables and routers.
Newbie... One who is new to a subject.
Newsgroup... Originally the name for discussion groups on USENET, but now more widely used in relation to discussion groups.
NIC... Network Information Center, an office that handles information for a network. Also Network Interface card, which is the card within a computer that you plug a network cable into.
NICAD... Nickel Cadmium battery.
NIMH... Nickel Metal Hydride battery.
Node... A single computer connection to a network or on a network.
NOP... No Operation.
NOR... Not Or logical operator.
NTFS... (New Technology File System) a means of organising files on a hard disk running under NT or XP platforms.
NTSC... National Television Standards Committee.
NUL... Null.


OCR... Optical Character Recognition.
OEM... Original Equipment Manufacturer.
OLED... Organic Light Emitting Diode.
Open Source Software... Is software for which the source code is freely available to users so that they may understand it, rewrite it, and compile new versions of the software.
.ORG... Non Profit Organizations (As part of domain name).
OS... Operating System.
OS/2... Operating System/2 - developed by IBM.


Packet Switching... The method used to transport data on the Internet. The data coming from the source computer is broken up into blocks or packets, each block has the address of where it came from and where it is going to. This enables packets of data to travel by different routes.
PAL... Phase Alternating Line - in TV system.
PASCAL... (Programming Language named in honour of Blaise Pascal).
Password... A (usually secret) code used to gain access to a system.
PB... Petabyte (1,024 terabytes).
PCI... Peripheral Component Interconnect/Interface.
PCMCIA... Personal Computer Memory Card International Association.
PDF... Portable Document Format.
PERL... Practical Extraction and Report Language.
PGDN... Page Down.
PIA... Peripheral Interface Adapter.
ping... To send a signal in order to check whether a server is running on the network.
PIPO... Parallel In, Parallel Out.
PIXEL... Picture Element.
PLL... Phase Locked Loop.
Plug in... A fragment of code that can be added to existing software to widen it's scope.
PNG... Portable Network Graphics, an image format designed for internet use.
PNP... Plug And Play.
POP... Post Office Protocol, how your Email client software fetches your mail from your ISP.
Port... Most commonly, a plug and socket (or software) communications connection. Port also refers to translating a piece of software to run on a different type of computer to that which it was originally designed for.
Portal... Can be used to indicate a major site that links to other web sites or it can mean a linking interface that will lead you to another website from the one that you are surfing.
POST... Power-On Self Test.
Posting... A message placed on to a network or the act of placing it.
PPP... Point to Point Protocol, a common protocol used to connect home computers to the Internet over telephone lines.
PRAM... Parallel Random Access Machine, pronounced 'P' RAM.
PRF... Pulse Repetition Frequency.
Program... A set of instructions that are written in a code that the computer can understand and react to.
Protocol... A set of rules that define the exact format of signals for communication between systems.
Proxy Server... An intermediate server that passes information between the client and the intended server.
PRTSC... Print Screen.
PSU... Power Supply Unit.
PW... Password.


Q words


RADAR... Radio Detection And Ranging.
RAID... Redundant Arrays of Independent Disks or Redundant Arrays of Independent Drives or Redundant Arrays of Inexpensive Disks.
RALU... Register Arithmetic Logic Unit.
RAM... Random Access Memory.
RDF... Resource Definition Framework, the rules by which the rules and protocols are themselves written.
REGEDIT... Registry Editor.
REM... Remark.
REN... Ringer Equivalence Number.
RET... Return.
RF... Radio Frequency.
RGB... Red, Green, Blue.
RISC... Reduced Instruction Set Computing or Computer.
RLL... Run Length Limited.
ROM... Read Only Memory.
Router... The hardware device (or software) that decides over which route a packet of data will be sent to reach it's destination.
RPN... Reverse Polish Notation.
RPT... Repeat.
R/T... Receive/Transmit or Radio Transmission.
RTAM... Remote Terminal Access Method.
RTC... Real-Time Clock.
RTF... Rich Text Format.
RTL... Resistor/Transistor Logic or Right To Left.
R/W... Read/Write.
RX... Receiver.


S/N... Signal to Noise ratio.
SCR... Silicon Controlled Rectifier or Screen.
Screen... An alternative name for a monitor.
SDSL... Symmetric Digital Subscriber Line, a version of DSL where the upload speeds and download speeds are equal.
Search Engine... A web based robot used for searching for specified information on the Web.
SECAM... Sequential Color With Memory (tv system).
Security Certificate... A piece of information that is used by the SSL protocol to establish a secure connection.
SEO... Search Engine Optimization, is the practice of writing web pages in such a way that the search engines rate your page highly and will thus offer them high in any ranking when a subject is searched for.
Server... A computer (or software) that provides a specific kind of service to other computers.
Servlet... A small computer program designed to be add functionality to the original server software (contraction of 'Server Applet').
SGRAM... Synchronous Graphics RAM.
SIMM... Single In-line Memory Module.
SIO... Serial Input/Output (communications driver).
SIP... Single In line Package.
SIPO... Serial In, Parallel Out.
SLIP... Serial Line Internet Protocol.
SMD... Surface Mounted Device.
SMS... Short Message Service.
SMTP... Simple Mail Transfer Protocol. The main protocol used to send electronic mail between servers on the Internet.
SNMP... Simple Network Management Protocol. A set of communication standards for devices connected to a TCP/IP network.
Spam... A deliberate attempt at broadcasting information or adverts by Email.
SO-DIMM... Small Outline DIMM.
SQL... Structured Query Language, a language used for interrogating databases.
SSL... Secure Socket Layer. A protocol to enable authenticated communications across the Internet in encrypted form.
STP... Secure Transfer Protocol.
SVGA... Super Video Graphics Array.
SYS... System.
Sysop... System Operator. A person responsible for the day to day operations and administration of a computer network.


TCP/IP... Transmission Control Protocol/Internet Protocol, a set of protocols that defines the Internet.
Telnet... The command/program that allows logging on from a remote site. (perhaps working from home).
TEMP... Temporary.
Terabyte... Often 1,000 gigabytes, but more strictly 1,024 gigabytes.
Terminal... A keyboard and a display screen that allows you to send commands to a remote computer.
TFT... Thin Film Transistor (as in lcd displays).
TIFF... Tagged Image File Format.
TMP... Temporary.
Trojan Horse... Or just 'trojan', is a computer program that hides inside another program and can transfer data about the affected computer to it's originator or 'master'.
TT... Typewriter Text.
TTL... Transistor/Transistor Logic.
TTY... Teletype.


UDMA... Ultra Direct Memory Access.
UDP... User Datagram Protocol, part of the TCP/IP suite of protocols.
UHF... Ultra High Frequency.
ULA... Uncommitted Logic Array.
UNIX... A multi user computer operating system, often used on large or mainframe computers.
Upload... Transmitting data or files from the computer you are using to another computer.
URL... Uniform Resource Locator, some say Universal Resource Locator, an address on the internet.
URN... Uniform Resource Name, for an address to be a 'URN' an institution has to commit to maintain the resource at that address permanently.
USART... Universal Synchronous/Asynchronous Receiver/Transmitter.
USB... Universal Serial Bus.
USENET... A system of discussion groups, with comments passed among hundreds of thousands of machines the world over.
UUENCODE... Unix to Unix Encoding is a method of converting files from binary to ASCII and back again, so that they may be sent across the Internet via Email.


VB... Visual Basic.
VBRUN... Visual Basic Runtime.
VESA... Video Electronics Standards Association.
VGA... Video Graphics Array.
VHF... Very High Frequency.
VLINK... Visited Link in HTML body tag.
Virus... A piece of code that replicates itself automatically and/or disrupts or damages files or the normal operations of the computer.
VPN... Virtual Private Network, a network in which some of the parts are connected using the public Internet, the data exposed on the Internet is encrypted, so that the entire network is considered 'virtually' private.


W3... see WWW.
W3C... World Wide Web Consortium.
WAN... Wide Area Network, a network that extends over an area larger than a single building or corporate site.
WAP... Wireless Application Protocol (as used in mobile phones).
.WAV... Waveform Audio - file name extension.
WDM... Windows Driver Model.
Web... Short for 'World Wide Web' it refers to the spidery nature of the connections and cross connections between nodes.
Web page... In it's strict sense - a document written for viewing in a web browser, but commonly used to indicate a group of pages or an entire web site.
Web Mirror... A server located in another region of the world that duplicates files for easier availability and speed of retrieval.
WIN 9.X... Windows95 or Windows98.
WIN CE... Windows Compact Edition, used on some palmtop computers.
WINE... Windows Emulator.
WINSOCK... Windows Open Systems Architecture.
WORM... Write Once, Read Many times. And also a type of virus that does not infect other programs. It makes copies of itself, and infects additional computers and it may alter, install, or destroy files on the infected machine.
WWW... World Wide Web, an immense collection of hypertext servers that serve web pages to browsers on demand.
WYSIWYG... What You See Is What You Get.


XMIT... Transmit.
XML... eXtensible Markup Language or eXtended Markup Language - uses sets of tags for defining data formats.
XOR... Exclusive OR logical operator.
XP... Cross Platform. (A term hi-jacked by Microsoft for and edition of their operating system).
XPFE... Cross Platform Front End, software methods that will work and appear similar to the operator on different operating systems.
XSL... Extensible Style Language.
XTAL... Crystal.


Y2K... Year 2000.
(Y/N)?... Asks for a Yes or No decision.


ZIF... Zero Insertion Force - a type of socket used for CPU Chips.
.ZIP... Compressed File - file name extension.

 Originated... 20 August 2003, Revised... 04 October 2003, New Domain... 04 November 2003, Revised... 29 April 2004, Upgraded... 17 July 2006,
This page has actually been validated by W3C Javascript Navigational elements removed as per W3C Link Checker version 4.1 (c) 1999-2004 Requirements
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