the most important program that runs on a computer. Every general-purpose computer must have an operating system to run other programs. Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers.
For large systems, the operating system has even greater responsibilities and powers. It is like a traffic cop -- it makes sure that different program and users running at the same time do not interfere with each other. The operating system is also responsible for security, ensuring that unauthorized users do not access the system.
Four major functions of operating system
Operating systems perform the following important functions:
1. Processor Management: It means assigning processor to different tasks which has to be
performed by the computer system.
2. Memory Management: It means allocation of main memory and secondary storage
areas to the system program, as well as user programs and data.
3. Input and Output Management: It means co-ordination and assignment of the different
output and input devices while one or more programs are being executed.
4. File System Management: Operating system is also responsible for maintenance of a
file system, in which the users are allowed to create, delete and move files.
5. Establishment and Enforcement of a Priority System: It means the operating system
determines and maintains the order in which jobs are to be executed in the computer
6. Assignment of system resources, both software and hardware to the various users of the