terminology. If you are already aware of most of these
terms, you may choose to read over them briefly and
continue to the other areas of this chapter. If you are just
beginning to learn about personal computers and word
processing, however, we recommend you study these
terms carefully.
NOTE: Although the following terms are
commonly used, they are not all inclusive. Be aware
that these are not the only terms you will hear used by
computer-literate persons. In your efforts to become
computer literate, we recommend you take
responsibility for obtaining as much knowledge about
computers as possible, either through on-the-job
training, self-study programs, or formal classroom
instruction.
AMERICAN STANDARD CODE FOR
INFORMATION INTERCHANGE (ASCII).— In
computer language, an ASCII code is a convention that
assigns a standard binary code to each upper- and
lowercase character, numeral, and typographical
symbol.
BAR CODE.— This inventory and sales computer
code is a machine-readable code consisting of ink lines
(bars) that represent information such as a product
description and price.
BINARY.— You will hear the word binary used to
represent a computer code that is made up of two
possible components or states—zeros or ones.
BIT.— This is the smallest unit of information in a
binary computer, represented by a single zero or one.
The word bit is a contraction of binary digit.
BYTE.— A sequence of bits, usually eight, treated
as a unit of computation or storage is known as a byte.
CATHODE-RAY TUBE (CRT).— The CRT is a
television-like display device with a screen that lights
up where it is struck from the inside by a beam of
electrons. (A CRT is simply referred to as a computer
screen.)
CENTRAL PROCESSING UNIT (CPU).— The
CPU is the part of a computer that interprets and
executes instructions. It is commonly referred to as the
brain of the computer. The CPU is composed of an
arithmetic logic unit, a control unit, and a small amount
of memory.
COMMAND.— A command is a statement such as
PRINT or COPY that sets in motion a preprogrammed
sequence of instructions to a computer.
COMPUTER.— Simply stated, a computer is a
programmable machine that accepts, processes, and
displays data.
CURSOR.— This is a moving spot of light that
indicates a point of action or attention on a computer
screen. The cursor shows you where you are on the
screen.
DAISY-WHEEL PRINTER.— This printer has a
circular print element consisting of thin stems, with
characters on their ends, radiating from a central hub
(like a daisy).
DATA BASE.— This is a popular term that refers to
a collection of facts about a subject or subjects divided
into files and records that are organized for easy access.
DIGITAL.— Digital is a commonly used term
pertaining to the representation, manipulation, or
transmission of information by discrete (on-off) signals.
DIRECT MEMORY ACCESS (DMA).— This
term refers to the mechanism or characteristic that
allows data to be transmitted directly between a
computer’s input and output ports and its temporary
memory.
DISK.— Spelled either disk or disc, a computer disk
is a round magnetized plate, generally made of plastic
or metal, used for storing data.
DISK DRIVE.— The disk drive is the mechanism
in the computer that rotates a storage disk and reads or
records data.
DOT-MATRIX PRINTER.— This printer uses a
pattern of dots arranged in rows and columns to print
text or graphics.
FLOPPY DISK.— A floppy disk, either solid or
flexible, is a small, portable disk used to store
information or instructions.
A floppy disk is a
convenient, portable way of storing information.
HACKER.— Often an avid experimenter with
computers.
HARD COPY.— A commonly used term referring
to printed computer output, usually on paper. (Simply
stated, hard copy is the printed copy.)
HARD DISK.— A rigid metallic platter coated on
both sides with a thin layer of magnetic material where
digital data is stored. Hard disks have more storage
capacity than floppy disks but are usually permanently
installed in a computer’s disk drive and are thus less
portable.
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