It is the interface between the user and the computer hardware.

some examples of an operationg systems are : UNIX, M.S.DOS, MS-WINDOWS etc.

Types of Operating System (OS) :

1. Batch Operating System
2. Multiprogramming Operating System
3. Multitasking Operating System
4. Time Sharing Operating System
5. Real Time Operating System

Definations :

• Batch Operating System :

The users who using a batch operating system do not interact with the computer directly.

• Multiprogramming Operating System :

It is an ability of an operating system that executes more than one program using a single processor machine.

• Multitasking Operating System :

It is allowing a user to perform more than one computer task (such as the operation of an application program) at a time.

• Time Sharing Operating System :

A time shared operating system uses CPU scheduling and multi-programming to provide each with a small portion of a shared computer at once.

• Real Time Operating System :

It is a special-purpose operating system used in computers that has strict time constraints for any job to be performed.

Some Important Functions Of Operating System :

1. Process Management
2. Memory Management
3. Input - Output Management
4. File Management
5. Scheduling Management
6. Security Management
7. Error Management
8. Time Management
9. Communication Management
10. Processor Management

Definations :

• Process Management

Process management involves various tasks like creation, scheduling, termination of processes, and a dead lock.

• Memory Management

Memory management is the functionality of an operating system which handles or manages primary memory and moves processes back and forth between main memory and disk during execution.

• Input - Output Management

it handles input to and output from attached hardware devices, such as the keyboard, mouse, monitor, hard disks, and printers.

• Scheduling Management

the activity of the process manager that handles the removal of the running process from the CPU and the selection of another process on the basis of a particular strategy.

• Security Management

the process of ensuring OS integrity, confidentiality and availability.

• Error Management

Error handling refers to the response and recovery procedures from error conditions present in a software application.

• Time Management

the process of organizing and planning how to divide your time between different activities.

• Communication Management

the operating system manages communications between all the processes.

• Processor Management

Process Management refers to aligning processes with an organization's strategic goals, designing and implementing process architectures, establishing process measurement systems that align with organizational goals, and educating and organizing managers so that they will manage processes effectively.