The word computer once meant a person who did computations, but now it refers to electronic devices. Computers can do much more than calculate. They help now to solve many important and complicated problems in science, engineering and business. Electronic devices are widely used in scientific research, industrial design and production; they control the work of plants and power stations, calculate the trajectories of spaceships and help people to discover new phenomena of nature. Computers can make tomorrow's weather forecast, translate from and into foreign languages as well as play chess, write poetry or compose music.
Since the invention of the Internet, computers have also been used to collect information from digital libraries situated all over the world, to send and get electronic messages (email), as well as to work, shop, and bank from home.
Computers save a lot of time and energy, operate at a great speed, store large quantities of information, carry out long and complex operations. How long does it take you to multiply the large numbers? In one third of a second, a computer can multiply two 128-digit numbers. In one second, it can add 4,000 five-digit numbers; in two seconds, it can solve 320 division problems. The same machine does the work of thousands of mathematicians faster and without the errors, which human beings can make.
The machine can display the results of data processing on a screen, can print them on paper, and store them away on magnetic tapes or disks. The electronic machine can give an accurate and fast answer or combination of possible answers from the information, which is stored on it. But ... it is human beings who think, who feed information into the machines. Computers work for us, but they do not think for us.