The document defines operating systems and describes their basic components and functions. It discusses how operating systems provide an interface between hardware and software, manage system resources, and allow for the execution of user programs. The goals of an operating system are to provide convenience for users and efficient operation of the computer system. An operating system is a type of system software that coordinates hardware and software and controls and allocates resources.

1. OPERATING SYSTEMS
Operating Systems
Basics of Operating Systems
Definition of Operating Systems
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2. Recap
In the last class, you have learnt about
• History of Operating System
• Types of Computers
• Different types of Operating Systems
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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
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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
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5. Components of a Computer System
A computer system can be divided into four
components
• Hardware
• Operating System
• Application Programs
• Users
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6. Abstract View of a Computer System
User 1 User 2 User 3 User n
System and Application Programs
Operating System
Computer
Hardware
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7. Hardware
• Physical components of a computer system
Ex: - I/O devices, Memory devices, CPU etc.,
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8. Software
• Set of programs
Program: - A finite set of sequence of instructions
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9. Types of Software
• System Software
• Application Software
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10. System Software
It provides an interface between software and
hardware
• Operating System
• Assembler
• Compiler
• Interpreter
• Linker
• Loader etc.,
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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.,
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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
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13. Design of Operating System
• User Point of View
• Computer System Point of View
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14. OS - User Point of View
• For ease of use
• To maximize resource utilization
• To compromise between usability and resource
utilization
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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
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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
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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
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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
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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
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20. Quiz
1. Which is the System Software?
a. MS-WORD
b. MS-EXCEL
c. WINDOWS
d. MS-ACCESS
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21. Quiz
2) Which one is not a system software?
a) Databases
b) Interpreter
c) Compiler
d) Assembler
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22. Other subject materials
• Web designing
• Micro processors
• C++ tutorials
• java
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