1. Name:- Nitish Xavier Tirkey
F.Y.BCA
Date:- 4th October, 2010

2. Flow of presentation
 Introduction
 Structure of OS
 Main function of Operating system
 Some popular Operating system
 Conclusion

3. Introduction
 Operating system is an integrated set of program that
controls the resources of a computer system and provides its
users with an interface or virtual machine that is easier to
use than the bare machine
 Operating System is a software, which makes a computer to
actually work.
 It is the software the enables all the programs we use.
 OS acts as an interface between the application programs
and the machine hardware.

4. Structure of OS
 The two primary objectives of an operating system are:
(1). Make a computer system easier to use:- An operating
system hides details of hardware resources from
programmers and other users and provides them with a
convenient interface for using a computer system.
(2). Manage the resources of a computer system:- An
operating system manages all the resources of a computer
system. Efficient and fair sharing of system resources
among users and/or programs is a key goal of all operating
systems.

5. Structure of OS
Users
Other system
Operating System
Computer Hardware

6. Main function of Operating system
 A separate module of operating system software performs
each of the function:
(1).Process management:- Process management module
takes care of creation and deletion of processes, and
providing mechanisms for synchronization and
communication among processes.
(2). Memory management:- Memory management module
takes care of allocation and de-allocation of memory space
to programs in need of this resources.
(3). File management:- It takes care of file-related activities
such as organization storage, retrieval, naming, sharing, and
protection of files.
(Contd..)

7. Main function of Operating system
(4). Security:- Security module protects the resources and
information of a computer system against destruction and
unauthorized access.
(5). Command interpretation:- Command interpretation
module takes care of interpreting user commands, and
directing system resources to process the commands.

8. Some popular Operating system
 Operating System can also be classified as:-
(1). Single User Systems:-They are popularly associated
with Desk Top operating system which run on standalone
systems where no user accounts are required.
Example: DOS.
(2). Multi User Systems:-Provides regulated access for a
number of users by maintaining a database of known users.
Refers to computer systems that support two or more
simultaneous users.
Example: Unix, Microsoft Windows NT.

9. Conclusion
 Without Operating system the computers cannot run the
application and we cannot do work in the computer.
 Therefore Operating system is very important in computer.

10. Thank you