Computers

= = COMPUTERS==

A computer is an electronic device that can store, retrieve, and manipulate data, or information. Computers run on programs. Programs are lists of instructions. Computers can be as small as a wristwatch. They can also be large enough to fill several rooms. Personal computers fit on top of a desk and can perform a wide variety of tasks. Tiny computers are used to control other machines, like cameras, washing machines, and airplanes. '''A microchip. Computers with chips run at amazing speeds.'''

Astrid & Hanns-Frieder Michler/Photo Researchers, Inc.

'''A computer is a machine that stores data. Data is another word for information. It can also change data. For example, computers can add numbers. They can show maps or videos. Our world depends on computers more each day.'''

'''Computers come in many sizes. Tiny computers can run a watch or a calculator. Large computers can run a bank’s business. Personal computers, or PCs, fit on a desk. People use them for writing, finding information, and lots of other jobs.'''

'''Computers run on programs. Programs are lists of instructions. They tell the computer what to do. The first computer with a stored program was built in the 1940s.'''

'''Computers also have their own languages. Most computers run on the binary system. It is made of two numbers: zero and one. Zero means no. One means yes.'''

'''New ideas have made computers smaller. Computers once ran on vacuum tubes. Then they ran on small circuits called transistors. Now they run on tiny circuits. These circuits are on computer chips. The chips are made of silicon. Computers with chips run at amazing speeds.'''

'''In 1981, IBM made the first personal computer. This meant people could use computers in their homes. As they became more popular, people called them PCs. Four years later, the first dot-com domain name was registered. This was the beginning of the Internet.'''

'''In the 1990s, the Internet grew. The Internet is a network that connects computers. They are connected over phone lines and cables. On the Internet, a computer can find information. People can find news. They can send messages. They can listen to music and watch videos.'''

'''Today, computers are small and fast. Computers not only sit on our desks, they fit in our pockets. People use laptops, notebooks, tablets, and smart phones everywhere they go. They use them in millions of different ways. They are part of everyday life.'''