1

Operating Systems Basics of Operating Systems Definition of Operating Systems

OPERATING SYSTEMS

2

Recap

In the last class, you have learnt about

• History of Operating System

• Types of Computers

• Different types of Operating Systems

3

Objectives

On completion of this period, you would be able to know

• System Resources

• Types of Software

• Operating System viewed from User and System

perspective

• Goals of Operating System

• Definition of Operating System

4

System Resources

What is a resource?

• A resource, or system resource, is any physical or

virtual component of limited availability within a

computer system

• System resources include– Hardware

– Software

5

Components of a Computer System

A computer system can be divided into four components

• Hardware

• Operating System

• Application Programs

• Users

6

User n

ComputerHardware

System and Application Programs

User 1 User 2 User 3

Operating System

Abstract View of a Computer System

7

Hardware

• Physical components of a computer system

Ex: - I/O devices, Memory devices, CPU etc.,

8

Software

• Set of programs

Program: - A finite set of sequence of instructions

9

Types of Software

• System Software

• Application Software

10

System Software

It provides an interface between software and

hardware

• Operating System

• Assembler

• Compiler

• Interpreter

• Linker

• Loader etc.,

11

Application Software

Designed to work on an operating system

MS-Office Suite

MS-Word

MS- Power point

MS-Excel

MS-Access

Databases

Utilities etc.,

12

Operating System

• It is an important part of almost every computer

system

• It is easier to define an Operating System by what

it does than by what it is

• It provides an environment to other programs to

do useful work

13

Design of Operating System

• User Point of View

• Computer System Point of View

14

OS - User Point of View

• For ease of use

• To maximize resource utilization

• To compromise between usability and resource

utilization

15

OS - System Point of View

• OS as a resource allocator

• OS as a manager of these resources

• OS as a controller of I/O devices and user

programs

• Operating system as a control program, which

manages the execution of user programs

16

Goals of Operating System

• To provide

– convenience for the user

– Efficient operation of the computer system

• Operating system is a way to solve the problem

by providing a usable computing system

17

Definition

• Operating system is a system software

• It coordinates between hardware and software

• It is an interface between hardware and software

• It controls and manages resources

• It executes programs on behalf of users

18

Summary

• Components of computer system

– Hardware, Software, Users

• Hardware : Physical components

• Software : Set of programs

• Operating System goals: Ease of use, efficient

operation of the computer system

• OS is a system software, which coordinates, manages

and controls resources on behalf of users

19

Frequently Asked Questions

1. List the components of a computer system

2. What should be the Operating System from user

and system point of view?

3. Define Operating System

20

Quiz

1. Which is the System Software?

a. MS-WORD

b. MS-EXCEL

c. WINDOWS

d. MS-ACCESS

21

2) Which one is not a system software?

a) Databases

b) Interpreter

c) Compiler

d) Assembler

Quiz

Other subject materials

22

• Web designing

• Micro processors

• C++ tutorials

• java

home