Types of Computers

There are several methods of classifying computers. The main distinction is between digital and analog devices.

Digital computers are so called because they process data that is represented in the form of discrete values (e.g. 0,1,2,3....) by operating on it in steps. Discrete values occur at each step in the operation. Counting on one’s fingers is probably the simplest digital operation we all know.

Analog computers are kinds of measuring instruments such as thermometers and voltmeters with pointers on circular dials. They process data in the form of electrical voltages, which are variable like the variable positions of a pointer on a dial. The output from analog computers is often in the form of smooth graphs from which information can be read.

Hybrid computers, as their name suggests, are computers that have the combined feature of digital and analog computers.

Digital computers are by far the most widely used.

It is also possible to classify computers by their use.

A Word Processor is a special purpose computer used in the production of office documents, letters, contracts, etc. Note: a general purpose computer can run a word processor program and hence temporarily become special purpose.

A Home Computer is a low-cost microcomputer of limited capability designed for domestic use with programs that typically are used for such things as computer games or controlling family finance.

A Personal Computer is a microcomputer designed for independent use by an individual at work or in the home mainly for business purpose. Some PCs are portable. Many can be connected to minicomputers and mainframe computers so that the PC users can also gain access to the facilities offered by the larger machine.

A Desktop Computer is any computer design for use on a desk in an office. Therefore home computers and PCs are types of Desktop computer.

A workstation is another kind of desktop computer. Although larger more powerful PCs are sometimes called workstations the term is normally used to imply the presence of advanced features not provided by all PCs.

A Lap-Top Computer is a PC sufficiently small and light for its user comfortably to use it on his or her lap.

An Embedded Computer is one that is within some other device or system but is not accessed directly. For example, there are embedded computers operating within petrol pumps, watches, cameras, video recorders and many types of domestic and industrial equipment.

It is also possible to classify computers by their size.

There are mainframes, minicomputers and microcomputers. However, there are no sharp dividing lines between them. For example, a model at the top of a manufacturer’s range of minicomputers might well be more powerful than the model at the bottom of a range of mainframes.

Thus, computers are classified according to their size, power, and type of processing unit.

The most powerful type of computer is the mainframe computer. Only large companies are likely to use a mainframe computer, as these machines are very expensive to buy and run.

A minicomputer is the next size down, a sort of ‘small mainframe’. It is a slower, less powerful version of the same class of computer, and is designed for businesses who do not need (or cannot afford) the capacity and speed of the smallest mainframe.

The smallest type of computer is the microcomputer. The name derives not from the small size of the machine – although the largest microcomputers can fit comfortably on a desk - but from the fact that the main processing circuits are on a single silicon chip, known as a microprocessor.

From the office worker’s point of view the main difference between the two categories is that of location: mainframe and minicomputers require their own special room, often air-conditioned, and trained computer staff to operate them, whereas microcomputers can be found dotted round the building, wherever there is a need for one.

Vocabulary Notes

digital – цифровий

value ['vxljH] –мат. величина

to occur [q'kW] –траплятися, мати місце

circular ['sWkjulq] – круговий, круглий

а dial – циферблат

variable ['vFqriqbl] –перемінний

voltage – напруга

smooth – гладкий, рівний, плавний

feature – особливість, (характерна) риса

a purpose – ціль

temporarily – тимчасово

limit – обмежений

domestic – домашній

mainly – в основному

although [Ll'Dqu] – хоч

access ['xkses] –доступ, мати доступ до

embedded computers – вмонтований, вкладений

to imply [Im'plai] – значити, означати, бути наслідком чогось

mainframe – універсальна обчислювальна машина