Glossary of Computer Terms

Computer Terms Glossary

This page is meant to serve as a guide to the vast quantity of computer terms and acronyms in common use for the casual computer user. It is divided into two main sections, the first is dedicated to the basics and is meant more for beginners, while the second is meant instead to be used as a reference. In reality many of the terms in the second section are still quite common; the first section was deliberately kept as short as possible.

Terms in the second section may be looked up by either using the "find in page" function of your browser, or by appending "#term" (without the quotes and where term is the term of interest) to the "URL" or "go to" section of your browser, keeping in mind that case matters. The best method of searching for a term though is to use the Search Interface that will return not only the specific term sought but also other entries that reference it. Be aware that the terms referenced in the second part of this page will freely assume familiarity with the first part.

If you are instead actually trying to figure out what a particular filename extension means, you might instead try the filename extensions page.

If you want something added or see a problem with something already here (but keep in mind this guide is not meant to be overly technical) please send .


The Internet is the world-wide network of computers. There is only one Internet, and thus it is typically capitalized (although it is sometimes referred to as "the 'net"). It is different from an intranet.


Commonly used to abbreviate the word "internationalization". There are eighteen letters between the "i" and the "n". Similar to (and often used along with) i18n.
The iCalendar standard refers to the format used to store calendar type information (including events, to-do items, and journal entries) on the Internet. iCalendar data can be found on some World-Wide-Web pages or attached to e-mail messages.
A small graphical display representing an object, action, or modifier of some sort.
Loosely speaking, a disk format sometimes used by MS-Windows, Mac OS, AmigaOS, and (rarely) UNIX. EIDE is enhanced IDE; it is much faster. Generally IDE is inferior (but less expensive) to SCSI, but it varies somewhat with system load and the individual IDE and SCSI components themselves. The quick rundown is that: SCSI-I and SCSI-II will almost always outperform IDE; EIDE will almost always outperform SCSI-I and SCSI-II; SCSI-III and UltraSCSI will almost always outperform EIDE; and heavy system loads give an advantage to SCSI. Note that although loosely speaking it is just a format difference, it is deep down a hardware difference.
A compiled, object-oriented language optimized for creating interactive fiction.
infrared communications
A device with an infrared port can communicate with other devices at a distance by beaming infrared light signals. Two incompatible protocols are used for infrared communications: IrDA and ASK. Many devices support both.
Instant Messenger
AOL's Instant Messenger is is a means of chatting over the Internet in real-time. It allows both open group discussions and private conversations. Instant Messenger uses a different, proprietary protocol from the more standard IRC, and is not supported on as many platforms.
interactive fiction
Interactive fiction (often abbreviated "IF" or "I-F") is a form of literature unique to the computer. While the reader cannot influence the direction of a typical story, the reader plays a more active role in an interactive fiction story and completely controls its direction. Interactive fiction works come in all the sizes and genres available to standard fiction, and in fact are not always even fiction per se (interactive tutorials exist and are slowly becoming more common).
If a program is interpreted, its actual human-readable source is read as it is run by the computer. This is generally a slower process than if the program being run has already been compiled.
An intranet is a private network. There are many intranets scattered all over the world. Some are connected to the Internet via gateways.
IP is the family of protocols that makes up the Internet. The two most common flavors are TCP/IP and UDP/IP.
Internet relay chat is a means of chatting over the Internet in real-time. It allows both open group discussions and private conversations. IRC programs are provided by many different companies and will work on many different platforms. AOL's Instant Messenger utilizes a separate incompatible protocol but is otherwise very similar.
The Infrared Data Association (IrDA) is a voluntary organization of various manufacturers working together to ensure that the infrared communications between different computers, PDAs, printers, digital cameras, remote controls, etc. are all compatible with each other regardless of brand. The term is also often used to designate an IrDA compliant infrared communications port on a device. Informally, a device able to communicate via IrDA compliant infrared is sometimes simply said to "have IrDA". There is also an earlier, incompatible, and usually slower type of infrared communications still in use called ASK.
An Internationalized Resource Identifier is just a URI with i18n.
The variant of UNIX designed by Silicon Graphics, Inc. IRIX machines are known for their graphics capabilities and were initially optimized for multimedia applications.
An integrated service digital network line can be simply looked at as a digital phone line. ISDN connections to the Internet can be four times faster than the fastest regular phone connection, and because it is a digital connection a modem is not needed. Any computer hooked up to ISDN will typically require other special equipment in lieu of the modem, however. Also, both phone companies and ISPs charge more for ISDN connections than regular modem connections.
An Internet service provider is a company that provides Internet support for other entities. AOL (America Online) is a well-known ISP.