Childrens Illustrated Encyclopedia

COMPUTERS

139

HOW COMPUTERS WORK

A computer converts everything it handles, such as letters of the alphabet,
into numbers. The numbers are stored in the computer in the form of

electronic signals in which “on” stands for 1 and “off” stands for 0. All
numbers, letters, and pictures are represented by sequences of 1s and 0s.

This is called binary code. The computer does all its different tasks, such
as inserting a word into

a sentence, by doing
rapid calculations with

these numbers. Once it
has finished its job, the

computer changes the
numbers into words

and pictures that we
can understand. SOFTWARE
The programs that make a computer perform different
tasks are called software. A computer can perform many
different jobs simply by using different software programs,
from computer games and word-processing packages to
painting programs and scientific applications that do
complex calculations.

NEW

TECHNOLOGY

Computers are

becoming increasingly portable and versatile. Wireless,

or “Wi-Fi,” technology means they can connect to the

Internet via radio signals, and the similar “Bluetooth”

enables them to communicate without cables over short

distances with pocket computers, cell phones, and even

printers, keyboards, and mice.

Tablets can send

and receive emails,

be used as cell

phones, and let 

you work on files

from your desktop

computer.

Find out more

Electronics

Machines

Mathematics

Robots

Technology

All computers contain a

set of microchips (left).

Inside a microchip

are millions of tiny

electronic parts that

store and process

electronic signals.

Using wireless

connections, a

laptop computer

can be used to

send emails or

surf the Internet

from almost

anywhere.

HISTORY OF COMPUTERS

In 1834, English inventor Charles Babbage designed the

first programmable mechanical computer. However, he

could not make the machine, as it was too complex for

the technology of his day. The first electronic computer,

ENIAC, was built in the US in 1946. During the 1980s,

transistors and microchips enabled computers to

become smaller and more powerful. Easy-to-

use software programs, such as those

developed by Microsoft (below),

encouraged the spread

of computers in

people’s homes.

In the 1990s, web

browsers opened

the Internet to

private individuals.

In 1975, American Bill Gates

(born 1955) founded the

Microsoft company. By the

late 1990s, Microsoft was

supplying more than half

the world’s software.

Bluetooth

Cell phone

Router

connected

to Internet

or local

network

HARDWARE

Computer machinery is called hardware. There

are many different kinds of hardware: personal

computers, small portable computers, and large

mainframe computers on which many people can

work simultaneously. Hardware also includes

components such as monitors, printers, and

other computer equipment (below).

Wi-Fi

Scanner built into printer

can turn images from

photos or books into data

usable by the computer.

Monitor displays

information.

Speakers are built

in to the computer.

Printer produces paper

copy of images or data

Keyboard from computer.

Mouse