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 .


Running a program is how it is made to do something. The term "execute" means the same thing.


Random access memory is the short-term memory of a computer. Any information stored in RAM will be lost if power goes out, but the computer can read from RAM far more quickly than from a drive.
random access
Also called "dynamic access" this indicates that data can be selected without having to skip over earlier data first. This is the way that a CD, record, laserdisc, or DVD will behave -- it is easy to selectively play a particular track without having to fast forward through earlier tracks. The other common behavior is called sequential access.
The Resource Description Framework is built upon an XML base and provides a more modern means of accessing data from Internet resources. It can provide metadata (including annotations) for web pages making (among other things) searching more capable. It is also being used to refashion some existing formats like RSS and iCalendar; in the former case it is already in place (at least for newer RSS versions), but it is still experimental in the latter case.
Something that happens in real-time will keep up with the events around it and never give any sort of "please wait" message.
The Restructured Extended Executor is an interpreted language designed primarily to be embedded in other applications in order to make them consistently programmable, but also to be easy to learn and understand.
Reduced instruction set computing is one of the two main types of processor design in use today, the other being CISC. The fastest processors in the world today are all RISC designs. There are several popular RISC processors, including Alphas, ARMs, PA-RISCs, PowerPCs, and SPARCs.
A robot (or 'bot for short) in the computer sense is a program designed to automate some task, often just sending messages or collecting information. A spider is a type of robot designed to traverse the web performing some task (usually collecting data).
The adjective robust is used to describe programs that are better designed, have fewer bugs, and are less likely to crash.
Read-only memory is similar to RAM only cannot be altered and does not lose its contents when power is removed.
RSS stands for either Rich Site Summary, Really Simple Syndication, or RDF Site Summary, depending upon whom you ask. The general idea is that it can provide brief summaries of articles that appear in full on a web site. It is well-formed XML, and newer versions are even more specifically well-formed RDF.
Ruby is an interpreted, object-oriented language. Ruby was fairly heavily influenced by Perl, so people familiar with that language can typically transition to Ruby easily.
Rust is a compiled language inspired by not just languages like C but also more unusual languages like Haskell and Erlang.