Operation System Assignment 2022

UNIT-IIUNIT-II
OPERATING SYSTEM

Operating system Introduction
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Operating system is the
interface between user and
hardware.
Software:collection of
programs
O.S is the s/w that is loaded into
computer memory when the
computer starts u p[BOOTING]
Def:An Operating System is a
collection of system programs
that together controls the
operations of a computer system

Objectives of OS
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Managing the
computer’s
hardware.
processor
Memory
Disk space
Providing an
interface (user
interface).
User can easily
access any
application

Process & Thread
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Process: A process is the execution of a program
Thread:Thread is an execution unit that is part of
process
A process can have multiple threads, all executing
at the same time.
It is a unit of execution in concurrent
programming.
A thread is lightweight

Functions of O.S
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Process Management:It creates, deletes ,suspension ,
resu me and schedule the processes.
Memory Management:It allocates and de allocates
memory space required by various programs.
File Management: It creates, delete, organize,retrieve
and stores the files and directories.
Device Mangement:It manages all the devices of the
computer system such as printers and modems and
detects the failu re of any h/w device and notifies the
user.
Secu rity Mangement:It protects the system resou rces
and information against u nauthorized use.
User Interface: It provides the interface between user
and h/w.