194 Glossary

file extension — The three characters following the period (pronounced “dot”) at the end of a file name. The extension indicates the type of file. Examples are .exe for program files and .hlp for help files. See also file name.

folder — Also called directory. A container for organizing files saved to a disk. A folder is symbolized on screen by a graphical image (icon) of a file folder. A folder can contain files and other folders.

format — (verb) To prepare a blank disk for use with the computer’s operating system. Formatting creates a structure on the disk so that the operating system can write information to the disk or read information from it.

frontside bus — The primary pathway (bus) between the CPU and the computer’s main memory. Also called “system bus.” See also

bus.

function keys — The keys labeled F1 through F12, typically located on the keyboard. Their function is determined by the operating system and/or individual programs.

G

gigabyte (GB) — A unit of data equal to 1,073,741,824 bytes

 

 

(1024 x 1024 x 1024 bytes). See also byte.

 

ground — A conductor to which all components of an electric

 

circuit are connected. It has a potential of zero (0) volts, is

 

connected to the earth, and is the point of reference for voltages

H

in the circuit.

hard disk — A storage device composed of a rigid platter or

 

 

platters that can be magnetically coded with data. Hard disks hold

 

much more information than diskettes and are used for long-term

 

storage of programs and data. The primary (or only) hard disk in

 

a computer is usually fixed, but some computers have secondary

 

hard disks that are removable. By default, the primary hard disk

 

is referred to as drive C.

 

hardware — The physical components of a computer system.

 

Compare software.