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 .


A computer language designed to be both fairly lightweight and extremely portable. It is tightly bound to the web as it is the primary language for web applets. There has also been an OS based on Java for use on small hand-held, embedded, and network computers. It is called JavaOS. Java can be either interpreted or compiled. For web applet use it is almost always interpreted. While its interpreted form tends not to be very fast, its compiled form can often rival languages like C++ for speed. It is important to note however that speed is not Java's primary purpose -- raw speed is considered secondary to portabilty and ease of use.
JavaScript (in spite of its name) has nothing whatsoever to do with Java (in fact, it's arguably more like Newton Script than Java). JavaScript is an interpreted language built into a browser to provide a relatively simple means of adding interactivity to web pages. It is only supported on a few different browsers, and tends not to work exactly the same on different versions. Thus its use on the Internet is somewhat restricted to fairly simple programs. On intranets where there are usually fewer browser versions in use, JavaScript has been used to implement much more complex and impressive programs.
A jiffy is 1/60 of a second. Jiffies are to seconds as seconds are to minutes.
A joystick is a physical device typically used to control objects on a computer screen. It is frequently used for games and sometimes used in place of a mouse.
The JSON is used for data interchange between programs, an area in which the ubiquitous XML is not too well-suited. JSON is lightweight and works extremely cleanly with languages languages including JavaScript, Python, Java, C++, and many others.
JSON-RPC is like XML-RPC but is significantly more lightweight since it uses JSON in lieu of XML.