What is a computer?

A computer is a machine that performs logical and mathematical operations on data and outputs the results in a form that can be understood by a person or a machine. The first computers were used mainly for mathematical calculations and performed addition, multiplication, division, etc. Modern computers are used to solve more diverse tasks. Including for processing text, graphics and processing huge arrays of information.

Devices that perform the simplest calculations are usually called calculators. They work according to strict algorithms, process button presses. Although general-purpose computers are often controlled by commands entered from the keyboard, their main functions are controlled by software, or programs. The work of both calculators and universal computers comes down, mainly, to the manipulation of symbols of a special kind.
What are computers

Computers are divided into two main types: analog and digital, are different principles of construction, methods of internal communication of information, response to the received command.

An analog computer when working imitates what it calculates. It continuously varies its characteristics. His reaction is an analogue of the process embodied in the problem. A universal analog computer has resistors, capacitors, inductors, connections between which reflect the conditions of the problem.

There are many different types of analog computers. They are "programmed" by setting the physical characteristics of their components. In some analog computers, this is done by turning individual components on and off from the circuits connecting them and changing the parameters of variable resistances, inductances, and capacitances in the circuits.

In addition to these technical tools like automatic transmission cars and music synthesizers, analog computers and used to perform specific computational tasks.

Digital computers manipulate binary numbers, or bits, that represent the conditions of the problem to be solved. In a digital computer, numbers can be used to represent other information, such as letters, operations "plus", "minus", etc. In contrast to analog computers, digital computers work in finite steps.

In addition, there are so-called hybrid computers, which as the name suggests, combines characteristics of both analog and digital computers.

Digital computers use a relatively small number of basic functions needed to perform tasks. The most important characteristics of these computers are speed, reproducibility of results, and versatility. Due to these properties, digital computers find very wide applications in a wide range from clocks to spacecraft.

The basic scheme for such computers was proposed by J. von Neumann in the late 1940s. A computer is a logical connection of blocks that have a specific purpose. Aggregated blocks are often called subsystems, which consist of smaller blocks serving a specific purpose. Those, most often, consist of even smaller blocks and components.

The digital computer consists of five major subsystems: the arithmetic logic unit (CPU), control unit, memory subsystem, internal communications and input-output.

From the moment of its creation, the computer became a universal device, a tool used in almost any profession. The use of computers no longer requires employees to be computer specialists. Therefore, specialized computer service centers are of particular importance. For example, such as service center "Computer Service in Uzhgorod"Experts who have extensive experience troubleshooting computers.