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 file is a unit of (usually named) information stored on a computer.
Sort of in-between hardware and software, firmware consists of modifiable programs embedded in hardware. Firmware updates should be treated with care since they can literally destroy the underlying hardare if done improperly. There are also cases where neglecting to apply a firmware update can destroy the underlying hardware, so user beware.
An extremely common type of removable disk. Floppies do not hold too much data, but most computers are capable of reading them. Note though that there are different competing format used for floppies, so that a floppy written by one type of computer might not directly work on another. Also sometimes called "diskette".
The manner in which data is stored; its organization. For example, VHS, SVHS, and Beta are three different formats of video tape. They are not 100% compatible with each other, but information can be transferred from one to the other with the proper equipment (but not always without loss; SVHS contains more information than either of the other two). Computer information can be stored in literally hundreds of different formats, and can represent text, sounds, graphics, animations, etc. Computer information can be exchanged via different computer types provided both computers can interpret the format used.
function keys
On a computer keyboard, the keys that start with an "F" that are usually (but not always) found on the top row. They are meant to perform user-defined tasks.


A frequently asked questions file attempts to provide answers for all commonly asked questions related to a given topic.
An incredibly fast type of serial port that offers many of the best features of SCSI at a lower price. Faster than most types of parallel port, a single FireWire port is capable of chaining many devices without the need of a terminator. FireWire is similar in many respects to USB but is significantly faster and somewhat more expensive. It is heavily used for connecting audio/video devices to computers, but is also used for connecting storage devices like drives and other assorted devices like printers and scanners.
fixed width
As applied to a font, fixed width means that every character takes up the same amount of space. That is, an "i" will be just as wide as an "m" with empty space being used for padding. The opposite is variable width. The most common fixed width font is Courier.
Flash memory is similar to RAM. It has one significant advantage: it does not lose its contents when power is lost; it has two main disadvantages: it is slower, and it eventually wears out. Flash memory is frequently found in PCMCIA cards.
In a simplistic sense, a font can be thought of as the physical description of a character set. While the character set will define what sets of bits map to what letters, numbers, and other symbols, the font will define what each letter, number, and other symbol looks like. Fonts can be either fixed width or variable width and independently, either bitmapped or vectored. The size of the large characters in a font is typically measured in points.
A language developed in 1970 by Moore. Forth is fairly portable and has versions on many different platforms. While it is no longer an very popular language, many of its ideas and concepts have been carried into other computer programs. In particular, some programs for doing heavy-duty mathematical and engineering work use Forth-like interfaces.
FORTRAN stands for formula translation and is the oldest computer language in the world. It is typically compiled and is quite fast. Its primary drawbacks are portability and ease-of-use -- often different FORTRAN compilers on different platforms behave quite differently in spite of standardization efforts in 1966 (FORTRAN 66 or FORTRAN IV), 1978 (FORTRAN 77), and 1991 (FORTRAN 90). Today languages like C and Java are more popular, but FORTRAN is still heavily used in military software. It is somewhat amusing to note that when FORTRAN was first released back in 1958 its advocates thought that it would mean the end of software bugs. In truth of course by making the creation of more complex software practical, computer languages have merely created new types of software bugs.
A free variant of Berkeley UNIX available for Alpha and x86 based machines. It is not as popular as Linux.
Freeware is software that is available for free with no strings attached. The quality is often superb as the authors are also generally users.
The file transfer protocol is one of the most commonly used methods of copying files across the Internet. It has its origins on UNIX machines, but has been adapted to almost every type of computer in existence and is built into many browsers. Most FTP programs have two modes of operation, ASCII, and binary. Transmitting an ASCII file via the ASCII mode of operation is more efficient and cleaner. Transmitting a binary file via the ASCII mode of operation will result in a broken binary file. Thus the FTP programs that do not support both modes of operation will typically only do the binary mode, as binary transfers are capable of transferring both kinds of data without corruption.