The Hermit Hermit's Free Library  Codes, Symbols, & Terms

Glossary of Computer Terms

A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - PQ - R - S - T - U - V - WXYZ


The drive designator for floppy disk drive A.


A DOS prompt which indicates that the current drive is A and the current directory is the root directory.


A prescribed set of well-defined rules or processes for the solution of a problem in a finite number of steps.

active window

Active window is the term used to denote the application window which is currently selected. It is sometimes said that the active window "has the focus". Windows for other applications which may be open at the same time are said to be inactive, or in the background.

alpha-numeric keys

All keys on the keyboard which produce characters and numbers.

application program

A program written for or by a user that applies to his own work.


Freeing up space on the active storage system by moving infrequently-used data files to off-line storage.


American Standard Code for Information Interchange. A standard format for storing and exchanging information between binary-based computers.

ASCII file

A disk file containing only ASCII characters 32 - 126, ie. only alpha-numeric characters and punctuation. Also known as a DOS or text file.

backspace key

Keyboard key which moves the cursor back one space, erasing the character (or code) which occupied that place.


The measurement of the rate at which information can be transferred across a network or the Internet. A wider bandwidth means more information can be transferred during a given amount of time.


Abbreviation for binary digit. The smallest unit of information storage in a binary computer system. Eight bits constitute one

block functions

Selection of existing text (data) for manipulation such as copy, delete, move, underline, print, etc.

boiler plate

Term describing the individual components of document assembly.


The emphasis of text by printing it darker than normal.


Booting is the process of loading an operating system into computer primary memory (RAM).


Networks of compromised computers (robots) used to perpetrate eFraud and eCrime.


Software for navigating the World Wide Web and retrieving hypertext documents as well as other files.


Bus is an electrical term which denotes a conductor used in common by several circuits. A computer system's data bus is a set of conductors which connect input and output devices, the microprocessor (or CPU), and primary and secondary memory so that they can communicate among themselves.


One byte (or eight
bits) is the amount of storage space needed to represent one character on a binary computer system.


The DOS prompt indicating that the current drive is C (the first hard disk on a hard disk system) and the current directory is the root.

Command and Control (C&C)

The method of using a computer or computer network (peer-to-peer) to exercise control over a botnet.


A data processor that can perform substantial computation, including numerous arithmetic or logic operations, without intervention by a human operator during the run.
A central processing unit, with main storage, input/output channels, control units, direct access storage devices, and input\output devices connected to it.

computer program

A series of computer instructions that are designed to accomplish a task or achieve a particular result.


The DOS command used to make an exact duplicate of a disk file.


Central Processing Unit. A CPU consists of a microprocessor and a certain amount of onboard RAM. Using built-in instructions as well as those from software programs, the CPU controls and coordinates the functions of other hardware devices and performs arithmetic calculations.


Cathode Ray Tube. An output device. The component of a computer monitor which displays text or images.

Cryptovirologic extortion

Efraud involving the encryption of an individual or organization's data using malware in order to extort money for it's safe return.


Indication of current data-entry point on the computer screen. Usually a flashing rectangle or bar of light.

data diskette

A floppy diskette used for saving and storing data files.


A set of meaningful symbols.

data bus


decimal tab

Word processing feature which automatically aligns columns of numbers on the decimal point.


A default setting is a preset, or "out of the box" setting, as opposed to a setting which has been customized by the user.

delete key

The keyboard key which deletes the character at the cursor location.

dot pitch

Dot pitch is the amount of (empty) space surrounding each
pixel on a computer monitor. The smaller the dot pitch rating of a monitor, the closer the pixels can be displayed together and the sharper the resulting image. Typical dot pitch ratings are .26, .32, .45, etc., with the smallest number being the best quality.


Subdivision of a floppy diskette or hard disk drive. Used to organize data files much as folders within a filing cabinet.

disk storage

Storage on direct access devices that record data magnetically on rotating disks. Secondary storage.

disk drive

Electromechanical device which records and reads information to and from magnetic media (diskettes).


Magnetic media used for secondary storage. Floppy diskette.

document assembly

The process of creating word processing documents by combining segments of text stored separately as files or macros.

DOS environment

The DOS environment is like a bulletin board where messages can be left by and for DOS and some application programs. It is a reserved portion of memory which is 512k by default. This size is often inadequate and can be increased by using the SHELL command.

dot matrix printer

Output device which prints characters by impacting the paper with clusters (matrix) of individual pins (dots).


An ellipsis (...) appears after commands on a Windows application's menu which indicates that more information will be required in a dialogue box in order for the command to be carried out.


The process of ensuring the privacy of sensitive information being transmitted across the Internet.


In a record, a specified area used for a particular category of data.


A document or collection of related records treated as a unit and stored on disk.

file association

See file extension below.

file extension

An optional three characters separated by a period from a file name to further identify a disk file. In MS-Windows file extensions such as .DOC, .TXT, .HTM, .XLS, etc. are associated with a particular application program, enabling a user to launch the appropriate application and load a file by simply double-clicking on a file in Windows Explorer or My Computer.

file maintenance

The process of deleting, copying, moving, and generally organizing files logically in folders in a hierarchic disk structure.

file name

In DOS, between one and eight characters which identify a disk file. MS-Windows permits file names up to 256 characters.


A term used to describe the instructions which have been permanently burned into a ROM (Read Only Memory) chip.

floppy disk, or diskette

Magnetic media secondary storage. A flexible mylar plastic disc coated with a magnetic material.

flush right

The word processing text alignment which positions text flush against a specified right margin, creating a ragged left margin.


A folder is a location on a disk drive where files can be stored. The term folder is interchangeable with the term directory.


A set of characters whose appearance is defined by a combination of typeface, style, weight, and size elements.


Text printed in the bottom margin of each page in a word processing document.

forward slash

The character used to separate the structure levels of a URL. Adopted from the UNIX computer operating system.


File Transfer Protocol. The protocol used to upload and download files on the Internet.

functions of hardware

hardware functions

function keys

The group of keyboard keys labeled F1 -- F10 or F12. Used to enter commands or access program features.


A graphical file format used for simple graphics with relatively few colors. Compare with


A measurement of data storage capacity: one thousand megabytes, or 1,000,000,000 bytes. Abbreviated G. or sometimes Gb.

global search & replace

Search and replace every occurance of specified text or codes.

graphical user interface (GUI)

A visual, icon-driven interface for an operating system or application program.

hanging indent

A paragraph format in which the first line begins with one or more tab stops to the left of the remaining lines.

hard copy

Information in a readable form on paper. Printed copy.

hard page return

A manually placed page break, usually inserted with the Control-Enter keystroke combination. Hard page returns are represented by the [HPg] code in WordPerfect and by double-dashed lines in MS-Word.

hard disk

A secondary storage device in which the storage medium is several rigid aluminum platters coated with a magnetic material. Characterized by very large storage capacity and speedy retrieval.


Physical equipment, as opposed to the computer program or method of use. Mechanical, magnetic, electrical, or electronic devices. Examples: keyboard, system unit, monitor, disk drive, printer, etc. Contrast with software.

hardware functions

The five functions of computer hardware and examples of each:
  1. input (keyboard, mouse, microphone, digital camera, modem)
  2. output (monitor, printer, speakers, modem)
  3. primary storage (Random Access Memory)
  4. secondary storage (magnetic media, optical media, digital memory)
  5. processing (microprocessor)


Text printed in the top margin of a document.


(1) the default page loaded by a browser, or (2) a website's main page.


HyperText Markup Language. HTML formatting tags tell browsers how a World Wide Web document should be displayed. HTML documents have the extension .HTML on Unix servers and .HTM on MS-Windows servers. See also Hypertext.


HyperText Transfer Protocol. The protocol used by World Wide Web servers and browsers to exchange information. The most common transfer protocol on the Internet.

Hypertext, or hyperlink

A method of formatting which permits documents to be linked by causing specified words (or images) to "jump" to other documents when they are clicked on.

IBM compatible

Designation for any make of computer which is hardware and software compatible with the IBM family of microcomputers.


Data which has been processed or organized.


To set counters, switches, and addresses to zero or other starting values at the beginning of, or at prescribed points in a computer routine.

Internal commands

The DOS internal commands, which are the smaller, most frequently used commands, are all included within COMMAND.COM. Since COMMAND.COM is loaded into secondary memory, or RAM, when the computer system is booted, internal commands do not need to be located on disk and therefore can always be executed from any DOS prompt.


An internet is a group of networks connected together. Used with a capital "I" it refers to the global interconnection of networks.

Internet Worm

A program which distributes so many copies of itself to Internet servers that they often crash.


Internet Protocol. A protocol which determines how packets (discrete quantities of information) are addressed and routed. The second part of TCP/IP.


A high-level, object-oriented programming language developed by Sun Microsystems. Programs written in Java are cross-platform because they are compiled into bytecode which is interpreted to different hardware platforms by a virtual machine: the Java interpreter, or the Java runtime. Java applets can also be integrated into World Wide Web pages and provide features such as interactivity and animation.


A scripting language developed by Netscape Communications which is used to add interactivity and animation to World Wide Web pages. It is not the same as Java.

.jpg (.jpeg)

A type of graphical file format used for photographs or other graphics which are complex and have many colors. Compare to


Text which lines up straight on the left margin (left justified), the right margin (right justified), or both margins (full justification).


One thousand bytes. Also K or Kb.

laser printer

Output device which prints an entire page at a time by attracting toner particles to static charges on the paper surface.


Comparing, branching, and testing true or false to continue or to repeat instructions.


A common feature of application programs which "plays back" a sequence of commands and/or data entry with a single command.

mail merge

A word processing feature which creates standard documents by combining a template document and a database.

main frame computer

A large, fast, multiuser computer system with centralized processing and data storage.


One million bytes (characters). Measurement of data storage capacity. Abbreviated M. or sometimes Mb.


One million cycles per second. Used to measure the CPU's clock rate or speed. Abbreviated MHz.


An electronic device capable of performing arithmetic and logic operations on data, according to a stored program of instructions.
A self-contained desktop computer system utilizing a microprocessor.


A programmable processing circuit built on a single silicon chip.


Input/output device that converts computer signals (digital) to telephone system signals (analog) and back again to facilitate the transmission of data between computer systems.


Output device which displays characters and graphic images.


The main printed circuit board in a computer. At the minimum, a motherboard includes the microprocessor with its supporting chip set and RAM. Other circuits, such as video adapter, modem, network interface card, sound card, etc. are frequently plugged into the motherboard via expansion slots. This modular approach make computer hardware more easily and economically maintained and upgraded.

move command

The word processing or computer program feature which enables selected text to be moved within a document or between two documents. Windows programs use the keyboard shortcut Ctrl+X.


The family of Microsoft
operating systems which includes MS-Windows 95, 98, ME, NT4, 2000, XP, Win7, and Win8. Three of the most important characteristics of the MS-Windows operating systems are:

mules (money mules)

Work-at-home employees hired by cybercriminals.


Multitasking is a feature of operating systems which allows a user to load multiple applications programs into memory (RAM) at the same time and then switch between them (task switching).

newspaper columns

In a word processor document, the style of columns in which text is arranged from the top of the page to the bottom and then continues at the top of the page in the next column.


A processing location on a network. A workstation (client) or server.

operating system (os)

An operating system is a collection of software programs which performs special functions on behalf of applications programs. The three functions of all computer operating systems are to manage:
  1. Computer resources (i.e. "run the hardware")
  2. Processes (i.e. assign resources to and launch applications programs)
  3. Files (save, retrieve, and provide tools for the management of files)
A user interface is a special class of computer program running under the supervision of the operating system that allows a user to communicate with the os. Examples of operating systems include MS-Windows, Apple System X, Unix, Linux, and DOS.


The first line of a paragraph appearing by itself at the bottom of a page. See widow.


To send information over a packet-switched network, the information is divided into small "packets" which are identified and labeled with their source and destination addresses.

packet switching

The technology that makes possible large-scale computer networking. Instead of a dedicated connection between two computers, messages are divided up into packets and transmitted over a decentralized network. Once all of the packets arrive at the destination, they are reassembled.


The division of a document into pages of predetermined length, either manually or automatically.


A confidential set of characters which restricts access to a document, program, or computer system.


Attempting to induce individuals to divulge personal information which can then be used for fraudulent purposes. Also, spear-phishing, or sniping where a specific individual or company is targeted.

pinned list items

The pinned list is the portion of the MS-Windows Start Menu at the top of the left column, just above the most frequently used programs list. Users can add an item to the pinned list by putting a shortcut to a document, application, or printer, etc. in the Start Menu folder.


A pixel (picture, or "pix", combined with element) is generally defined as the smallest area on a monitor's display which can be lit up independently. On a color monitor, a pixel is actually composed of three sub-pixels (red, blue, and green) and is therefore the smallest area which can be lit up as a color.
See also resolution and dot pitch.


A graphical WYSIWYG display of a document in a word processing program.


A protocol is a format or a set of rules for communications between either computer hardware and software.


In an application program, a short on-screen message which assists the user by requesting information necessary to continue processing.


Request for information from a database based on specific criteria.


Random Access Memory. RAM is temporary, or primary, computer memory which is used to store instructions and data during processing. RAM is said to be volatile because its contents are lost when electricity is no longer being applied to it.


In database structures, a record is the collection of related data items (fields) which relate to one entity (such as a person, transaction, or inventory item) and are treated as a unit.


Resolution is the maximum number of pixels which can be displayed or reproduced by a computer monitor. Resolution is expressed as the number of pixels a monitor can display on one line by the number of lines which can be displayed. Therefore, a resolution of 1024 x 768 means a monitor can display 768 lines on the screen, each containing 1024 pixels. The greater the number of pixels which can be displayed in a given area, the smaller each pixel is and the better the quality of the resulting image. See also
pixel and dot pitch.


Read Only Memory. A type of computer memory which contains permanent instructions, said to be "burned-in". ROM programs are used to control hardware at a very low level and are considered to be part of an operating system. ROM is sometimes referred to as firmware because it has some characteristics of hardware (it is a chip) and some of software (it contains instructions).


A server, or network server, is a computer system which shares hardware and software resources, such as secondary storage, printers, application programs, etc., with network clients, or workstations.


The upward, downward, or sideway movement of information on a computer screen.


A set of instructions in a disk file which directs a computer to perform a specific set of functions. A program.


Unsolicited email messages. Leading source for eFraud and malware.

spelling checker

A word processing function which searches for and corrects misspellings by comparing a document's words with those in a built-in spelling dictionary.


SPAM delivered by instant messaging.

split screen

The word processing feature which permits the simultaneous display of (parts of) two or more documents.

system software

operating system.


Transmission Control Protocol/Internet Protocol. The protocol first used on the Internet which has now become the most widely-used network protocol.


Telnet is a terminal emulation protocol used to allow a user at a computer to log on to a remote computer and enter commands at a prompt as if they were directly connected.

Temporary Internet Files

Copies of web pages stored on a computer by a browser.


A model for other documents or files. Can contain formatting, styles, macros, and/or text.

thesaurus utility

A word processing feature that provides synonyms and antonyms from a built-in dictionary for specified words in a document.

typeover mode

The data entry mode in which new characters replace those already in the text.


A computer
operating system developed by Kerrighan and Richie at AT&T Bell Labs in the late 1960's. It was written entirely in the C programming language, which made it more easily ported between different hardware platforms. The Internet was originally built entirely upon Unix-based servers.


Universal Resource Locator. The address of a document or other resource on the Internet. A URL has three components: the protocol (http, for example), the server domain name (e.g., and the file name and location on the server (e.g. /it/def/gloss.htm).


One of the original Internet services, Usenet makes possible Newsgroups, which are like world-wide bulletin boards arranged by subject.

virtual memory

Virtual memory is an
operating system feature which uses secondary storage (the hard disk drive) to free up primary storage (RAM) in order to enable application programs to access more RAM than which is physically available.

Web-based email

Email services, usually free, which make it possible to send and receive email using a browser.


The last line of a paragraph at the top of a page by itself. See orphan.

window control buttons

In an MS-Windows application window, the control buttons, which are located at the right-hand side of the window's title bar, are used to control the mode in which the application is running or to close the application.




The word processing feature which automatically adjusts the length of text lines to maintain the specified left and right margins.


A workstation, or network client, is a machine which is connected to a network server for the purpose of utilizing hardware and software resources being shared by the server.


World Wide Web. The Internet service which uses the HTTP protocol to facilitate the exchange of both text and graphical information using hypertext links. The World Wide Web was developed in 1991 and although among the most recent Internet services, it has become the service with the most traffic.


The on-screen rendering of documents which is faithful to their printed format: What You See Is What You Get.