Presentation on topice Operating System. Structure of OS, Uses of OS, Advantages and Disadvantages of OS.

1. A PRESENTATION ON OPERATING SYSTEM
Name : SUMIT PAL
B.Sc. Agriculture 1st semester
HIT Code : 4668

2. INTRODUCTION
An Operating system is a collection of program that
controls and coordinates all the tasks and functions
in a computer system and mediates between
application programs and the hardware
components.
It enables a user to utilise hardware resources very
efficiently. So, operating system makes it easy for
user to use computer system.
Basically operating system has two objectives:
i. Managing the computer’s hardware
ii. Providing the interface

3. 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.

4. Functions of Operating System
The main functions of an operating system are as follows:
1) Process Management When two or more jobs are in queue (to be
processed), operating system decides which one of them will get the
attention of CPU.
2) Memory Management As a memory manager, the operating system
handles the allocation and deallocation of memory space as required by
various programs.
3) File Management It is responsible for creation and deletion, organising,
storing, retrieving, naming and protecting the files and directories.
4) Device Management It provides input/output sub-system between
processes and device drivers. It handles the device caches, buffers and
interrupts and detects device failures and notifies the same to the user.
5) Security Management It protects system resources and information
against destruction and unauthorised use, it keeps different program and
data in such a manner that they do not interface with each other.
6) User Interface It provide interface between user and hardware. The
interface consists of set of commands or menus through which a user
communicates with a program.

5. Types of Operating System
Real-Time Operating System It aims to execute real time applications such as auto pilot
mechanism used in aircrafts.
e.g. Windows CE, QNX, RTLINUX, VxWorks, Free RTOS, etc.
Single-User Operating System It is designed for one user to effectively use a computer at a
time.
e.g. Windows 95/NT/2000, etc.
Multi-User Operating System It allows many users to take advantage of the computer
resources simultaneously without affecting each other.
e.g. UNIX, VMS, Linux, Windows 2000, etc.
Single-Tasking Operating System It allows only single program to run at a time
e.g. F Palm OS, etc
Multi-Programming Operating System It allows to run several programs at a time using
time sharing and keeps several jobs in memory at a time.
e.g. Linux, Unix, etc
Multi-Tasking Operating System It is logical extension of multi-progamming operating
system and reduce CPU idle time.
e.g. Microsoft’s Windows and Apple’s Mac OS.
Multi-Processing Operating System uses two or more CPUs within single computer System.
e.g. Linus, Unix, Windows 2000, etc.

6. Advantages Of OS
• Easy to use
• User friendly intermediate between all hardware’s and software’s of the
system
• No need to know any technical languages
• It’s the platform of all programs
Disadvantages of OS
• If any problems affected in OS, you may lose all the contents which have
been stored already
• Unwanted user can use your own system.