The document discusses operating systems, defining them as system programs that coordinate devices and programs to operate a computer. It notes the need for an operating system and describes some examples like Windows, UNIX, and DOS. The document also covers the differences between single-user and multi-user operating systems, listing some examples of each type. Finally, it outlines several key functions of an operating system like managing programs, memory, devices, files, and more.

1. Need for Operating System & Types of Operating System
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2. Objective
On completion of this period, you would be able
to know
 What is operating system
 Need for operating system
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3. Prerequisite
What is the abbreviation of OS and DOS
OS stands for Operating System
DOS stands for Disk Operating System
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4. What is operating system?
Operating system is a system program used to
coordinate and control various devices and
programs in order to work with computer
machine
Examples
Windows 95
Windows NT
UNIX
DOS
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5. Operating system
 The operating system is a collection of programs
used to operate a computer system
 It takes the responsibility of computer’s overall
operation and supervision
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6. Operating System (contd)
 It coordinates among various devices and
programs, and provides an interface between a
programmer and the computer system
 OS is popularly used for the abbreviation of the
operating system
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7. Operating system (contd)
 Now, from the fastest supercomputer and
largest mainframe, right down to the smallest
embedded microprocessor, every computer
uses an operating system
 Over the years, a variety of operating systems
have evolved and many remain in use
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8. Operating system (contd)
 DOS became the most widely used
microcomputer operating system
 Today, DOS has been replaced on many
computers by more powerful operating systems
such as Windows, UNIX, Windows NT and OS/2
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9. Operating System (contd)
 More powerful operating systems make it
possible to run tasks on less expensive
microcomputers
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10. Types of Operating System
According to number of users
Single User Operating Systems
Multi User Operating Systems
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11. Single user & Multi user Operating Systems
 Only one user can work at a time on a computer
system with a single user operating system
 More than one user can work at a time on a
computer system with a multi user operating
system
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12. Some popular Operating Systems used are
Single user operating Multi user operating
system system
OS/2 UNIX
MS DOS VENIX
WINDOWS 95 XENIX
WINDOWS 98 LINEX
WINDOWS ME UNIXWARE7
WINDOWS XP WINDOWS NT
WINDOWS 2000 professional SUN SOLARIES
MACINTOSH OS NOVEL NETWARE
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13. Operating System performs the following
Functions
 Managing and controlling the execution of a
program
 Transfer data between primary memory and
auxiliary storage devices
 Start up the computer and perform diagnostic
tests of circuits and memory
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14. Operating System performs the following
Functions (contd)
 Accept commands entered at the keyboard that
allow you to control the computer system
 Managing peripheral devices
 Transfer data and command to the printer
 Managing files on external media
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