What are the parts of the operating system



When you start the computer, it takes a while before it is ready to use. Why is that? What happens while the computer is "starting up"?

The answer is: the operating system is being loaded. Today's computers would be inconceivable without an operating system. Without the user noticing much, it does a number of tasks that keep the computer working.

What is the operating system?

The operating system is software that manages and controls the hardware of a computer (e.g. RAM, drives, keyboard, screen) and coordinates it with the requirements of application programs. The operating system ensures that the user can work with the computer after switching on, i.e. that he can start, use and exit application programs. In a network, the operating system provides, among other things, ensure that several users can work at the same time without disruption. The operating system is therefore essential for computer operation. It is loaded into the RAM during the boot process

Most of the work is done by the operating system in the background; they remain hidden from the user. The operating system therefore seems to play a subordinate role for the user and is often viewed as part of the computer.

What are the tasks of an operating system?

Making the installed / connected hardware available: The operating system loads all files that are required to operate the hardware elements (graphics card, screen, keyboard, mouse, drives, etc.). The technical details are encapsulated by the operating system in such a way that they are neither visible to the operator nor to an application program. For example, the operating system translates real addresses into virtual addresses or it assigns the name "A:" to the real floppy disk drive via which this device is addressed.
Coordination and allocation of resources: This is the core task of a modern operating system. Important resources are processor capacity, main memory, other memories and input / output units. The allocation of processor capacity to the individual processes in multitasking determines the timing of programs.

Management and control of the data flow between software and hardware: This includes loading and checking the user programs, forwarding user entries, handling errors and managing user rights.

Provision of utilities: Auxiliary programs for data backup, text input (editor), telecommunications, voice input, drawing, arithmetic, etc.

Organization and management of the file system: The files are organized according to a certain principle and managed in catalogs. The user can create or delete directories and files or switch to a specific directory.

Interface for application programs: Provision of operating system functions for application programs (API). This interface is used by the application programmers. This allows application programs such. B. access certain hardware components (for example, a text program uses the corresponding function of the operating system for the "Print" command) or z. B. use an operating system controlled screen display. Since this interface differs between the individual operating systems, application programs do not run under all operating systems.

User interface: The user or the system administrator uses this to communicate with the computer. Nowadays it is usually implemented as a graphical user interface. The command interpreter (command processor) is also part of the user interface of an operating system. In some, especially Unix-based operating systems, the user interface is not assigned to the operating system kernel and is therefore referred to as the shell. The user interface allows the user to configure the computer, i. H. adapt the settings to the desired requirements (as far as possible), e.g. B. set the screen resolution.

For operating systems that allow multiple users, i.e. network operating systems, the Organization of multi-user operation added. Application programs are protected against unauthorized multiple access, databases that are accessed by several users are kept at a well-defined current status and user data is protected against unauthorized access.

additions

The work areas that are taken over by the operating system have expanded significantly in the course of development. A modern operating system performs many tasks that were previously left to the application programs, such as the organization of the screen display. In addition, the number of utilities included in the scope of delivery usually increases with each new version (e.g., unlike the previous versions, Windows ME, 2000 and XP contain the much more complex Media Player instead of the file media playback).

As a rule, only one operating system is active on a computer which is precisely tailored to the respective type of computer (PC, workstation, mainframe). The most important operating systems for home users are Windows 9x, Windows ME, Windows XP for the PC and MacOS for Macintosh computers. These operating systems are usually already installed when you buy a computer. DOS used to play a dominant role, and in the early 1990s OS / 2 also had a significant market share. Windows NT or Windows 2000 as well as Unix are used for multi-user operation. The latter is suitable for operating the entire range of computers, from PCs to workstations and minicomputers to mainframes. In recent years, Unix-based Linux has established itself as an inexpensive alternative for a PC operating system. In addition, there is a practically incalculable number of other operating systems, which are often adapted to a specific area of ‚Äč‚Äčapplication. Special network operating systems (e.g. Windows NT Server, Novell Netware) offer e.g. B. special network functions, real-time operating systems (real-time systems) process requests particularly quickly.