Generally, a computer is any device that can perform numerical calculations – even an adding machine, an abacus, or a slide rule. Nowadays, however, the term usually refers to an electronic device that can automatically perform a series of tasks according to a precise set of instructions.
The basic job of computers is processing of information. For this reason, computers can be characterized as devices, which accept information in the form of instructions (called a program) and characters (called data), perform mathematical and logical operations on the information, and then produce results of these operations. The data is raw material while information is organized, processed and useful for decision-making. Computer is used to convert data into information.
The “brains” of today's computers are integrated circuits (ICs), sometimes called microchips, or simply chips. Each of these tiny silicon wafers can contain hundreds of millions of microscopic electronic components designed for many specific operations. Some chips make up a computer's central processing unit, which controls the computer's overall operation; some are math coprocessors that can perform millions of mathematical operations per second; and others are memory chips that can each store billions of characters of information at a time. There are also circuits, which can make decisions. The kinds of decisions, which computer can make, are not of the type: "Who will win the war between two countries?" or "Who is the richest person in the world?" Unfortunately, the computer can decide only three things, namely1: Is one number less than another is? Are two numbers equal? and, Is one number greater than another is?
A computer can perform great numbers of arithmetic-logical operations without becoming tired2. This ''mechanical brain'' can find the solution to a problem much faster than a human being can… But a computer cannot do anything unless a person tells it what to do and feed to it the necessary data, i.e3 its capabilities are limited by the minds of human beings. It is a man who is the most important component of the computer system ... so far4.
Notes: 1namely – à èìåííî;
2without becoming tired – áåç óñòàëè;
3i.e. [that is] – òî åñòü;
4so far – ïîêà.