Computer is a device that processes information with astonishing speed and accuracy. Computers process information by helping to create it and by displaying it, storing it, reorganizing it, calculating with it, and communicating it to other computers. Computers can process numbers, words, still pictures, moving pictures, and sounds. The most powerful computers can perform tens of billions of calculations per second.
The computer has changed the way we work, learn, communicate, and play. Virtually every kind of organization throughout the world conducts business with computers. Students, teachers, and research scientists use the computer as a learning tool. Millions of individuals and organizations communicate with one another over a network of computers called the Internet. Computer games entertain people of all ages.
Almost all computers are electronic digital computers. They are electronic in their use of electric current (a flow of electric charge) to carry information. They are digital in that they process information as units of electric charge representing numbers. The word digital means having to do with numbers.
To enable a computer to process information that is not numerical–such as words, pictures, or sounds–the computer or some other device must first digitize that information. A device digitizes information by translating it into charges that represent numbers. After the computer processes the digitized information by working with the charges, the computer or a device connected to the computer translates its results back into their original form.
Thus, an artist might use a machine called a scanner to digitize a photograph. The artist would next process the resulting electric charges in a computer to change the photograph–perhaps to add a border. The artist would then use a printer connected to the computer to produce a copy of the altered photo.
Digital computers are one of two general kinds of computers. The other kind are calculating devices called analog computers. An analog computer represents amounts with physical quantities, such as distances along a scale, rather than with numbers.
The technology of computer hardware (the physical parts of computer systems) has advanced tremendously since 1946, when the first electronic digital computer was built. That machine filled a huge room. Today, a single microprocessor, a device the size of a fingernail, can do the same work as that pioneering machine.
The technology of software (programs, or sets of computer instructions and information) is also advancing rapidly. Early users of computers wrote their own software. Today, most users buy programs created by companies that specialize in writing software. Hundreds of thousands of different programs are available for businesses and individuals.
Because of advances in hardware and software, the price of computing has dropped sharply. As a result, the number of computers in operation has risen rapidly ever since the first commercial digital computers were manufactured in the 1950′s. More than 10,000 computers were in operation worldwide by 1961. Ten years later, the number exceeded 100,000. By 1990, about 100 million computers were running. By the mid-1990′s, the number had reached about 200 million.
Grammar Focus
3. Define the tense form of the highlighted verbs (Определите временную форму выделенных глаголов)