Ian Darwin's Top-100 Computing Glossary
The following list of definitions defines the one hundred
or so terms you most need to know.
This does NOT include the many texting abbreviations
that millenials use - just try to keep track of that!
If you encounter terms that are not covered here, you can
check if this page has been updated,
or you can try the
Free Online Dictionary of Computing
If you know of a definition that should be added, please
mail me (ian at darwinsys.com).
This page will be updated every so often; last updated
Wed Oct 20 09:19:34 EDT 2021
- A "smiley"; a facial expression turned sidways. Also "-g" for "grin".
- WiFi Wireless protocol standard
- See PDF
- Attached Graphic Processor (faster video updating on PCs)
- ALGOrithmic Language (European contemporary of FORTRAN)
- An operating environment for mobile devices, using the Linux OS and the Java and Kotlin languages
- American National Standards Institute
- from "A patchy server"; Apache.org has over a hundred open source projects, best known for their web server (originally a very heavily-patched version of the NCSA web server)
- Application Programmer Interface (contrast with ABI, B=Binary)
- a tiny program (Java applets used to run in web pages)
- any computer program
- American Standard Code for Information Interchange
ASCII - American Standard Code for Information Interchange, a 7-bit character set used in most computers, superceded by UTF-8
- Application Service Provider; also (Microsoft) Active Server Pages
- originally American Telephone and Telegraph
- audio mixer
- See mixer
- Measure of how fast one's connection is
- BATch file (MS-DOS name for command file or shell script)
- "Baudot". Normally treated as "bits per second"
- Basic Input/Output System (ROM-resident I/O routines)
- One "0 or 1"-level piece of information; the letter "a" requires 8 bits to store or send
- Extended version of DVD. Device firmware is written in Java.
- Bit-Mapped Picture (bitmap file format)
- The program you use to access the Web
- Berkeley Software Distribution; one of two main kinds of UNIX system (now available in several flavors; OpenBSD, NetBSD, FreeBSD, macOS, etc.
- Defect or error in a program
- build tool
- A program that runs other programs to build an application.
- Burroughs, Univac, NCR, Control Data and Honeywell - the 1970's BUNCH opposed IBM's hegemony in the mainframe computer market
- A character or other small chunk of information stored in 8 bits (today, but older computers have used 5, 6, 7 or 9-bit bytes)..
- Microsoft programming language, originally copied from Java
- Pioneering computer programming language used to write Unix, and many apps, before C++ and Java
- Programming language used in many windowed applications
- Canada (Many other two-letter domains are ISO country codes)
- A place where data is kept for reuse; browsers and CPU chips both have 'em
- (also Chromium), an open-source web browser funded by Google
- Customer Information Control System (long-serving IBM DBMS and database transaction server)
- Command-Line Interface, a terminal-mode connection to a computer system. Seems cumbersome compared with GUI but usually more concise and powerful
- A desktop machine; a program that uses a server program
- To re-write a computer program without using its original source code but retaining its interface.
- Complementary Metal Oxide Semiconductor (CMOS memory stores BIOS settings on PCs)
- COmmon Business Oriented Language - widely used by financial sector ~1960s to 2010s
- (Microsoft) Component Object Model
- Top level domain for COMmercial organizations; "command" (executable file - MS-DOS)
- To rewrite a file into a smaller format that can later recreate the original
- Common Object Request Broker Architecture, an RPC mechanism
- 1) Control Program for Microcomputers; 2) Critical Path Method
- Control Program for Micros; early operating system cloned to make MS-DOS
- Able to run on, or to generate programs that run on, multiple operating systems
- Canadian Standards Association
- Comma-Separated Values, a simple data interchange format
- Concurrent Versions System (a larger-scale replacement for RCS)
- A computer programming language, similar to Java, used in Flutter
- Data Base Management System
- (Microsoft) Distributed Component Object Model
- Digital Equipment Corporation, an early minicomputer maker, later absorbed by Compaq, which was in turn swallowed by HP
- (line) - a permanent link between two computers
- A computer used by one person at a time; the main view or workarea on a desktop computer's screen.
- Dynamic Host Configuration Protocol
- Dynamic HTML
- Working over the telephone with a modem
- Dynamic Link Library
- Direct Message, a message sent privately on a forum or social media site
- Direct Memory Access
- 1) DEC's Digital Network Architecture; 2) MS-Windows Distributed interNet Applications Architecture
- Domain Name Service
- area; see DNS
- Domain Name Service
- a distributed service for findind a computer's network address if you know its hostname and domain (or vice versa)
- Disk Operating System (used by many manufacturers; IBM 1965). See also MS-DOS
- Copy a file "down" from a larger device to a smaller (see Uplaod)
- drill down
- To navigate "down" towards a more-detailed information page. In GUI systems, may be represented by a drop-down control, or by a link to more information.
- A multiple choice control in a GUI. Usually indicated by a small down-pointing triangle.
- Digital Versatile Disk (initially Digital Video Disk) - CD-ROM format disk with higher density to store several hours of high-res video
- 8-bit character set used mainly by IBM mainframe computers
- A Java-centric IDE, and, the foundation that supports it and many other projects
- A web browser provided by Microsoft to run on MS-Windows
- See UEFI
- Extended ISA; a bus used on some IBM-style PCs
- Mail messages send electronically
- Original "smiley" (qv), now they have Unicode character ("code point") values.
- To rearrange the data in a message so it cannot (easily) be read by unauthorized persons
- Social Media site
- Frequently Asked Questions, a list of answers to questions people have asked in the past (except the one you need an answer to right now)
- First in, first out
- Software that reduces the volume of something. Examples: firewalls, SPAM filters, search keyword filters...
- Software that aims to protect you from malicious attack
- Obsolete graphical format from Adobe (Flash was plagued by security flaws most of its lifetime)
- A portable cross-platform toolkit supporting iOS, Android, MS-Windows, macOS, Linux, and Web from a single code base.
- FORmula Translator; early widely-used programming language, later versions still in use
- Free and Open Source Software
- Functional Programming: programming based on functions with no side effects
- free software
- Software that you can do what you like with
- "The worlds most scalable operating system": a BSD derivative, used by Apple as basis of Mac OS X and iOS, used by Microsoft to run its Hotmail service for many years
- File Transfer Protocol; an older protocol for copying files; OK for downloading but not for uploading
- 1: F***ed Up Beyond Any Recognition (attributed to US Military usage in World War 2); 2: Failed UniBus Address Register, pun on #1 name chosen for DEC PDP-11 machine instruction
- Giga-, 10**9, meaning a thousand million.
- Graphics Interchange Format, an older format for bitmap graphics files.
- A widely-used VCS
- A free (Microsoft-funded) site for open source code sharing
- GNU's Not UNIX (recursive acronym), a project to build a Unix-like system
- Humungous computer company famous for web search, oft used as a verb
- Google Code
- A defunct Google site for code sharing.
- An early competitor for HTTP: rarely used now.
- Government (DNS domain for US governmment)
- GNU Public License; like free software but with redistribution conditions
- A tool for searching in text. Often used as a verb IRL, e.g., "She grepped the apartment for her car keys."
- Graphical User Interface, common system with windowed desktop, computer and mouse or similar devices
- A functional programming language
- Home page
- 1) a site's main or welcome page; 2) the default page you see when you start your browser
- a computer on a network
- a name that can map to e.g., an IP address for a host. Also a service for looking up hosts.
- HyperText Markup Language, the language that most web pages are written in
- HyperText Transfer Protocol; protocol used (over TCP) to download web pages, images, etc.
- HyperText Transport Protocol; protocol used (over TCP) to download web pages, images, etc.
- Secure HTTP (HTTP over SSL)
- A link from one web page to another (occasionally to elsewhere in the same page)
- Text containing hyperlinks
- originally International Business Machines
- 1) A small image representing something in a computer desktop or app 2) An computer programming language
- Institute for Electrical and Electronic Engineers (standards body)
- Internet Engineering Task Force (one of several Internet standards bodies)
- Able to be used by people in different languages
- Interconnected Networks; used to refer to the worldwide connection of networks running the Internet Protocol
- Internet Protocol
- The protocol used to communicate among computers on the Internet and many local networks
- Internet Service Provider
- Company that rents you your internet access
- Apple's operating system for the iPhone
- Internet of Things; connecting small devices to the internet.
- see Internet Protocol
- Apple proprietary name for their line of Pads (see Pad).
- An Apple smartphone running iOS. Not the first smartphone, but the first to be well marketed.
- Apple proprietary name for their line music players (see MP3 player).
- Interrupt Request Queue
- Industry Standard Architecture (one of 5 expansion buses for desktop computers)
- International Standards Organization; also mistakenly used to mean "ISO-9660", their standard for CD-ROM formatting, as a synonym for CD-ROM-format disk filesystem.
- Internet Service Provider
- Very-obsolete name for Java Enterprise, which is now Jakarta
- Eclipse Foundation project to specify and implement the Java Enterprise APIs, using code base donated by Oracle (formerly JavaEE)
- Programming language first used in web pages but now one of the most widely used programming languages, particularly on the server side. Not an acronym; in particular, not "Just Another Vague Acronym" :-)
- Previous name for Jakarta, while it was managed by Sun and then Oracle
- Programming language used in the browser in most modern web sites; shares some syntax and keywords with Java but is not at all interchangeable with it
- Job Control Language (used for control language on several OSes including IBM mainframes)
- Joint Picture Experts Group, a newer format for bitmap image files.
- Java Server Pages
- A widely-used Java Unit Testing package
- Kilo-, 10**3, meaning thousand (either 1,000 or 1,024).
- "K Desktop Environment" (formerly K=Kool, "Kulow" the inventor's first name)
- A programming language that looks like simplified and modernized Java
- Kernighan & Pike, book "The UNIX Programming Environment"
- Kernighan & Ritchie, book "The C Programming Language"
- A file containing multiple subprograms
- Last in, first out.
- Any connection. Unix/Linux: extra name for a file. See also hyperlink
- A free operating system patterned loosely on Unix.
- A name used to authenticate yourself (needed on some sites, and to connect to a server via ssh or other protocol)
- Large Scale Integration (technique for building chips)
- Lempel-Ziv-Welch compression scheme, widely used; patent war fought over it in late 1990's
- Mega-, 10**6, Million (either 1,000,000 or 1024*1024).
- Desktop computers made by Apple; GUI-based; user-friendly; much of Windows 95 was copied from 1980's Macintosh software
- Macintosh Operating System
- MacOS X
- (the X was pronounced "Ten") - older versions of macOS, partly derived from BSD
- A build tool used on Unix, Linux, Windows and Mac
- Adding metadata to a file, e.g, HTML is a markup language that adds formatting information into what is otherwise a plain text file.
- A build tool used in Java
- MicroChannel Architecture, IBM's failed attempt to dominate expansion cards
- Microsoft Certified System Engineer
- Multitasking with Fixed Tasks (IBM mainframe OS)
- A Large computer company based in Redmond, WA.
- Microsoft Windows
- a family of operating systems for desktop computers
- Maker Input Format, Adobe Framemaker interchange format
- Military (DNS domain for US military)
- A device or program that blends multiple audio streams into one
- (Modulator-demodulator) Box that converts computer signals to telephone noise and back
MoDem (Modulator-demodulator) Box that converts computer signals to telephone noise and back
- The first graphical web browser; now defunct; basis of Netscape and Microsoft's browsers
- A computer input device, first devised by Douglas Englebart at SRI
- A software project to take over when Netscape closed down. Main projects are Firefox browser and Thunderbird email program
- Multi-processing or multi-processor
- A file format for storing digital audio, such as Music
- MPEG 3 (audio format)
- MP3 Player
- A small device for playing music files.
- A file format for storing digital video
- Motion Picture Experts Group (movie format)
- Microsoft Disk Operating System cloned from CP/M; OS distributed with the IBM PC; made Microsoft rich & famous
- Term used to differentiate Microsoft Windows from the general notion of window systems
- Multitasking with Virtual Storage (IBM mainframe OS)
- Multitasking with Variable Tasks (IBM mainframe OS)
- National Cash Register, a firm that got into computers early
- National Center for Supercomputer Applications (origin of Mosaic and NCSA Web Server, ancestor of Apache Web Server)
- Northern Electric (later became NorTel)
- 1) Network (DNS domain for network related agencies); 2) Microsoft's latest attempt to dominate the world
- "The world's most portable operating system": a BSD derivative
- The first and oldest commercial web browser
- Messages sent to a topic instead of a list of recipient(s)
- originally Northern Telecomm, a defunct Canadian telecommunications manufacturer.
- New Technology (it was a new try at writing a working MS-Windows system)
- (not an acronym; a pun on "New") Apple's failed attempt to dominate expansion cards
- Company that made CD-ROM drivers; early name of Java project
- Objective C
- An OOP extension of the C language, mainly used in Mac OS X
- A functional programming language
- Office Suite
- A collection of desktop applications for word processing, presentation, spread sheets, etc.
- Object Oriented Programming; developing sofware in which "classes" of "objects" in the program represent things in the real world
- "The world's most secure operating system": a BSD derivative
- Operating System
- The program that runs when you start a computer, and is in charge of running all other programs on that computer.
- A database company that is too big for its britches. Current owner of Java language.
- Organization (DNS domain for non-profit organizations)
- Operating System; also Open Source
- Obsolete Operating System # 2 (IBM's answer to MS-Windows)
- Open Systems Interconnection
- Open Source Software; OpenSource Sound System
- Early name at Xerox Parc for a computer tablet
- Palo Alto Research Center, Xerox campus that created the modern computer industry
- Patent troll
- A person or company that does zero research but buys up patents from dying companies and uses them to sue real companies to extract money without doing real work.
- Personal Computer; also Program Counter
- Peripheral Component Interconnect, the major bus for add-in cards on both PCs and Macintoshes today
- Personal Digital Assistant; replaced by smartphones
- Portable Document Format, a file format for sharing printable documents
- Practical Extraction and Reporting Language (aka Purely Eclectic Rubbish Lister) - computer programming language
- Program Evaluation and Review Technique, a management technique for evaluating software development
- Programmable Grid Array (technique for building chips)
- to "poke" a host to see if it is both connected and running (not an acronym; sometimes called Packet InterNet Groper but this is not "approved" by the program's inventor, the late Mike Muuss)
- Programming Language One; IBM procedural programming language
- A piece of software that extends another, such as a browser
- Portable Network Graphics (patent-free format to replace GIF)
- 1) point of presence (a remote ISP computer); 2) Post Office Protocol: how many users download their mail
- PostScript (PS)
- A page description language from Adobe, based on work at PARC. Nowadays PS files are normally converted to PDF.
- A piece of software; a set of directions to a computer on how to solve a task. Includes OS, applications, apps, etc.
- programming language
- A language used to express computer software
- Programmable Read Only Memory (BIOS chips used to be installed as PROMs for ease of updating)
- A set of standard for exchanging information (or data)
- A program that stands in for another; often in conjunction with a firewall
- public domain
- Information or data that anybody can use for anything
- An inqury that you send to a search enging
- Format and plug-in used for movies
- An interactive data exploration environment, originally cloned from S
- Random Access Memory
- originally Radio Corporation of America
- Revision Control System, a source-code maintenance program
- Format and plug-in used for playing audio
- To give your name, address and email to a site in exchange for a login
- Request For Comments (RFCs are the technical standards for the Internet)
- Reduced Instruction Set Computer
- Read Only Memory
- Remote Procedure Call (Sun, Microsoft, Java and others have their own RPC technology)
- Rivest-Shamir Algorithm
- Rich Text Format, Microsoft word-processor interchange format
- Read The F***ing (or "Fine") Manual
- An interactive data exploration environment, written at Bell Labs.
- originally Santa Cruz Operation, reseller and then maintainer of Xenix
- Secure Copy, part of SSH
- search engine
- A web site that lets you find information on other web sites
- A computer used by many people at a time; a program that provides a service
- Silicon Graphics Inc.
- Standard Generalized Markup Language (parent standard of HTML and XML)
- Obsolete Format and plug-in used to display animations.
- A protocol for secure messaging, and an App for mobile and desktop that uses it.
- A portable device containing a powerful computer and able to work as a telephone but also run many applications. Main types are Android and iPhone
- A few-byte symbol comprised of ASCII characters that represents a (usually sideways) facial expression, eg., ":-)" Being replaced by emoticons (qv)
- Symetric Multi Processing (i.e., two or more identical SPARC or Pentium chips in one computer)
- Simple Mail Tranfer Protocol (used to send mail to a server)
- System and Network Architecture (IBM mainframe strategy)
- social media
- Any site that allows users to login and post/share messages or other information (photos). Popular examples are Facebook, Twitter, Instagram
- Anything that a computer can interpret
- Sun's version of UNIX
- source code
- The form in which computer programs are written, in languages like Java, C++
- A free (ad-funded) site for open source code sharing
- Unwanted email (named after a Monty Python skit).
- Scalable Processor ARChitecture (Sun's CPU RISC design)
- Independent research organization, originally funded by Stanford University
- Secure Shell, a telnet/FTP replacement
- Secure Sockets Layer (used to encrypt HTTP, making HTTPS. Obsolete; replaced by TLS
- A functional unit that can be used by other programs.
- To register with a service such as mailing list
- Sun Microsystems
- Former large computer company, home of Java, Solaris, NFS, much more. Swallowed up by Oracle.
- Supervisor Call (IBM mainframe OS term for "system call")
- A mobile device with a screen size larger than a smartphone.
- Terminal Control Program; the layer above IP and used by e.g., HTTP, to send data
- remote terminal - do not use (use ssh instead)
- Running or examing a given subprogram or program to ensure that it works correctly.
- Thin client
- A computer designed to be permanently connected to a server, using programs from the server, and saving its data on the server
- The title of a web page; appears in the browser window's title
- Transport Layer Security; replacement for SSL
- A software development kit, a package of tools and libraries to make a particular kind of applicatino
- To abuse a person or group online, or send useless posts to waste their time; a person who does so.
- Time Sharing Option (IBM's early attempt at a timesharing system)
- Social Media site
- Unsolicited Commercial Email; another name for SPAM
- Unreliable Datagram Protocol; a "postcard" style protocol for less overhead than TCP; runs over IP; used by DNS
- A replacement for BIOS
- Multi-sized character set meant to contain all the world's characters. ASCII/UTF-8 are proper subsets; characters can be 8, 16 or 32 bits.
- Unit test
- Testing individual pieces of an application in isolation
- an operating system in continuous use for over fifty years. UNIX machines can be both client and server. Widely used by geeks and to provide internet services. Unix-like systems power both iOS and Android, hence, virtually all mobile devices.
- Copy a file from a smaller device to a larger, e.g., a camera to your desktop, your desktop machine to a server
- Universal Resource Locator; the address of one page or item on the Web
- Universal Serial Bus, modern way of plugging extras into a computer
- Old (user's net?) Collection of "news" sites; predates WWW
UTF-8 - 8-bit superset of ASCII character set
- Virtual Addressing Extension (DEC computer in 1980's/early 90's)
- Visual Basic
- Version Control System, sometimes called Program Librarian. Keeps track of all changes made to files such as the source code of a program
- A program that attaches to another program (most are harmful!)
- Visual Basic
- MS-Windows scripting language used to write simple applications
- Virtual Memory System (OS for VAX)
- Voice Over IP (telephony or voice traffic on the Internet)
- Another early competitor for HTTP.
- World Wide Web
- Web page
- One page of a web site
- The person(s) who maintain a given website; the email to send typos/correctsions on the site itself
- A private messaging application, acquired by Facebook.
- Service to find out who owns a domain
- "Wireless Fidelity", an industry term for 802.11 wireless networks. Widely used on mobile devices, smartphones, laptops, tablets, etc.
- A user-editable web site. Wikipedia was far from the first, but is the best known wiki.
- Rectangular regions of a screen; claimed as a trademark by Microsoft
- Communicating without wireless; usually implies radio but can also be Infrared (like TV remote)
- A series of characters; a storage location in computer memory. Claimed as a trademark by Microsoft.
- World Wide Web
- the collection of all HTTP servers worldwide connected via the internet
- A program that propagates itself from one computer to another
- World Wide Web
- A popular web comic (xkcd.com)
- eXtensible Markup Language; a document authoring language similar to HTML but with more flexibility and stricter coding requirements.
- Extreme Programming; also a Windows operating system version
- A social media site specifically for videos, run by Google
- A family of programs that compress and decompress files