|A computer is a
machine that can do a series of mathematical or logical tasks. It differs from a
calculator, which can do those things too, because a computer can store a program in its
memory so it can repeat is operations, make logical decisions, and store and get data
without a human telling it to do so.
in two forms: analog and digital. Analog computers give you data as physical, measurable
quantities. Car speedometers and electrical watt-hour meters contain analog computers.
Digital computers store information that is much more
complex. Your PC at home is a digital computer. PCs, or personal computers, store
information on a microprocessor.
Most PC systems have a monitor, keyboard, mouse, CPU
(which contains the memory and logic workings, and a storage device), and often a modem
A microprocessor is a circuit that contains the
arithmetic, logic and control circuits the computer needs to interpret and carry out
instructions contained in a computer program. The microprocessor is combined with other
microprocessors on a semiconductor base to form a computer chip. Then the microprocessor
becomes the heart of your PC, also called a microcomputer.
Calculators, digital watches and electronic games also
contain microprocessors. Your moms kitchen appliances or your houses alarm
system may also have microprocessors.
Computers become even more powerful when they are
connected through a network. Two or more computers are linked to exchange messages or
share information or system resources. There are two types of networks: a local-area
network and a wide-area network. A local-area network connects PCs and computer
workstations (called nodes) over dedicated, private communications links. A wide-area
network connects many nodes over long-distance communications links, such as telephone
The Internet is a wide-area network. It connects millions
of people through their computers throughout the world.
Click above to see a bigger picture of a computer.
Click above to see the inside of a CPU, or Computer
Click above to see a microprocessor.
Click above to see computer chips close up.