Computer,
machine that performs tasks, such as mathematical calculations or electronic
communication, under the control of a set of instructions called a program. Programs usually reside
within the computer and are retrieved and processed by the computer's
electronics, and the
program results are stored or routed to output devices, such as video display monitors or printers.
Computers are used to perform a wide variety
of activities with reliability, accuracy, and
speed. People use computers in a wide variety of ways. In business, computers track inventories
with bar codes and scanners, check the credit status of customers, and transfer funds electronically.
In homes, tiny computers embedded in the electronic circuitry of
most appliances control the
indoor temperature, operate home security systems, tell the time
,
and turn videocassette recorders
on and off. Computers in automobiles regulate the flow of fuel, thereby increasing gas mileage.
Computers -also entertain, creating digitized sound on stereo systems
or computer-animated
features from a digitally encoded laser disc. Computer programs, or applications, exist to aid every
level of education, from programs that teach simple addition or sentence construction to programs
that teach advanced calculus. Educators use computers to track grades and prepare notes; with
computer-controlled projection units, they can add graphics, sound, and animation to their lectures.
Computers are used extensively in scientific research
to solve mathematical problems, display
complicated data, or model systems that are too costly or impractical to build, such as testing the
air flow around the next generation of space shuttles. The military
employs computers in
sophisticated communications to encode and unscramble messages, and to keep track of personnel
and supplies.
