Operating system is a very complicated term. It does not have an exact definition, since it is a whole complex of programs, each of which performs a specific function, but in general they represent a single complex for managing a computer. The development of the "axis" takes a lot of time. Modern operating systems are being finalized after the release for several years.
An operating system is a set of various programs and applications that allow the simultaneous interaction of all devices of a personal computer. Various applications from the whole complex provide access to PC resources.

The operating system is applications that manage the main processes, various external modules (such as a printer, webcam, etc.), files, programs. Operating systems may differ in terms of operation, reliability and security, but their main function remains the same.
The operating system is the primary means of communication between the PC and the user. The OS is inherently the soul of the computer, without it, it will be just a collection of various devices, the use of which will be simple.impossible.
IBM compatible personal computers run on a wide variety of operating systems and environments. The choice of OS is carried out due to the functions that the personal computer will have to perform. For example, a powerful gaming station must be powered by Windows, while a PDA uses the Android operating system.
One of the most common PC systems:
- MS-DOS - OS, which is controlled using the command line. It is simple and reliable, but very difficult to manage. For convenience, several shells were developed, first Volkov Commander, and then the more popular Norton Commander.

- At the end of the twentieth century, Microsoft provided users with a completely new operating system - Windows. Management in it took place with the help of various "windows", which, in principle, formed the basis of the name. This system quickly gained popularity due to its ease of use and availability. Windows is currently the most popular operating system in the world.
Despite the differences in the program code and functions, the composition of the OS remains the same for everyone. Includes:
- a software module that provides communication with the file system;
- command processor - a program that provides the execution of commands that the user sets;
- a set of system drivers - programs that ensure the smooth operation of various external and internal modules. It is the drivers that are responsible for the operation of both the printer and the motherboard.fees;
- graphical interface module - a set of programs that allow you to use the mouse when entering a command;

- utilities - serving program disks. Operations with files also occur due to their use;
- information module - an application that provides information about the current state of the system.
Various physical media are used to store information (hard disk, flash card, etc.), but for the program to work, it must be loaded into internal - RAM. The speed of the PC directly depends on the amount of internal memory.