Glossary
This glossary includes terms and definitions from the
following publications.
The
American National Dictionary for Information
Systems
, ANSI X3.172-1990, copyright 1990 by the
American National Standards Institute (ANSI). Copies
may be purchased from the American National
Standards Institute, 11 West 42 Street, New York, NY
10036. Definitions are identified by the symbol (A).
The ANSI/EIA Standard 440-A:
Fiber Optic
Terminology
. Copies may be purchased from the
Electronic Industries Association, 2001 Pennsylvania
Avenue, N.W., Washington DC 20006. Definitions are
identified by the symbol (E).
The
Information Technology Vocabulary
, developed by
Subcommittee 1, Joint Technical Committee 1, of the
International Organization for Standardization and the
International Electrotechnical Commission (ISO/IEC
JTC1/SC1). These definitions are identified by the
symbol (I). Definitions from draft international
standards, committee drafts, and working papers being
developed by ISO/IEC JTC1/SC1 are identified by the
symbol (T), indicating that final agreement has not yet
been reached among the participating National Bodies
of SC1.
A
adapter. A printed circuit board that modifies the
system unit to allow it to operate in a particular way.
address. (1) A value that identifies a register or a
particular part of storage. The value is represented by
one or more characters. (2) The location in the storage
of a computer where data is stored. (3) To refer to a
specific storage location by specifying the value that
identifies the location.
application. The use to which an information
processing system is put; for example, a payroll
application, an airline reservation application, a network
application.
application program. (1) A program that is specific to
the solution of an application problem. Synonymous
with application software. (T) (2) A program written for
or by a user that applies to the user's work, such as a
program that does inventory control or payroll. (3) A
program used to connect and communicate with
stations on a network, enabling users to perform
application-oriented activities.
architecture. See computer architecture.
attenuation. A decrease in magnitude of current,
voltage, or power of a signal in transmission between
points.
AWG. American Wire Gauge.
B
back up. To copy information, usually to diskette or
tape, for safekeeping.
backup. Pertaining to a system, device, file, or facility
that can be used in the event of a malfunction or loss of
data.
BBS. Bulletin board system.
BIOS. Basic Input/Output System.
BIOS (Basic Input/Output System). Code that
controls basic hardware operations such as interactions
with diskette drives, hard disk drives, and the keyboard.
bit. Either of the digits 0 or 1 when used in the binary
numeration system. Synonymous with binary digit. (T)
bridge. A functional unit that interconnects two local
area networks that use the same logical link control
protocol but may use different medium access control
protocols.
buffer. (1) A routine or storage used to compensate
for a difference in rate of flow of data, or time of
occurrence of events, when transferring data from one
device to another. (A) (2) A portion of storage used to
hold input or output data temporarily.
bus. One or more conductors used for transmitting
signals, data, or power. See also address bus and data
bus.
byte. A string that consists of a number of bits, usually
8, that are treated as a unit and represent a character.
C
cable. The physical medium for transmitting signals; it
includes copper conductors and optical fibers.
cache. A buffer storage that contains frequently
accessed instructions and data; it is used to reduce
access time.
CD-ROM. Compact disc read only memory.
High-capacity read-only memory in the form of an
optically read compact disc. See also CD.
Copyright IBM Corp. 1998 177
