COMPUTER SOFTWARE - 3 (OPERATING SYSTEM)

• Operating System :- An Operating System is a master software program that controls the internal activities of the computer hardware and provide user interface. These interface can be either CUI (Command/Character User Interface) or GUI (Graphical User Interface). Application program need to interact with the Operating System fro using hardware resources.

          Operating is the Ist program loaded copied into the main memory of the computer after the booting.

Functions of Operating System ----

➝ Processor Management :- The operating system assigns processor (if the computer has more than one processor) to different task that must be performed by the computer.

➝ Memory Management :- It allocates main memory and secondary memory to the system program, user program and data.

➝ Input/Output Management :- It carries out I/O management, co-ordinates and assigns different input and output devices.

➝ File Management :- It manages files on various storage devices and transfer these files from one storage device to another.

➝ Scheduling :- It establishes and enforces the job priority, i.e, it determines and maintains the order in which jobs are to be executed in the computer system.

➝ Time Sharing :- It co-ordinates and assigns computers, assemblers, utility program and other software packages to various users working on the computer system.

⟶ Security Management :- It establishes data security and integrity, that is, it gives different programs and data in such a manner that they do not interface with  each other. Moreover, it also  provides protection to the data from being destroyed by any other user.

Classification of Operating System -------

➝ Single User Operating System :- Operating System which allows only one user to work on a computer at a time is known as Single User Operating System.

Ex￫ DOS(Disk Operating System)

➝ Multi User Operating System :- A multi user operating system allows a number of users to work together on a single computer. Each user will be provided a terminal connection to a computer.

Ex￫ LINUX, UNIX, Windows 2000 etc.

➝ Single Tasking Operating System :- Operating System which can execute on;y a single task at a time.

➝ Multitasking Operating System :- Multitasking Operating System supports execution of more than one job at a time. Most of today's operating system are multitasking such as Windows 2000, UNIX, LINUX, etc.