An operating system is a compilation of different computer programs, which executes the resources of the system like the working storage, the hard disk, or the in-/ and output hardware and give it to the application program. Through the connection, the operating system forms a cutting point between the hardware parts of the computer and the application software of the user.
They originally consist of a core, which executes the hardware and the programs help to start the computer and its system. For example, it helps to load the device driver. Nowadays we find operating systems in each category of a computer for example tablets, smartphones, or PC.
So we can summarize that the main task of the operating system is: user communication, loading programs, execution, to break programs, and to end programs, management and assignment of the processor time, management of the internal storage for applications.
The protection is also a role of the operating system and it has nowadays a higher meaning than the time before at the beginning of the 1990s.
Not only computers have operating systems. May with a special function they also exist in near all devices in which software is included. Starting with computer games, mobile phones, navigation systems, machines to control systems used in trains, cars, planes, or satellites.
