An Operating system is a collection of
integrated programs that provide recurring
services to the other programs or to the
user of a computer. These services consist
of disk management, file management, and
device management. Without an Operating
system a computer would be useless.
It is a function of an operating system that
allows users to interact with a computer. A
user interface program may include a
combination of menus, screen design,
An operating system manages a collection
of computer hardware resources by using
a variety of programs. Each hardware
device is controlled by a piece of software,
called a driver which allow the operating
system to activate and use the device.
The data management function of an
operating system govern the input &
output of the data & their location,
storage & retrieval.
The task management function of
operating system prepares, schedules,,
controls & monitors task submitted for
execution to ensure the most efficient
processing. A task is a collection of one
or more related programs & their data.
The operating system keeps
track of all the files on each
disk. Users can make file
management easier by
creating a hierarchical file
system that include folders
and subfolders arranged in a
Most modern operating System, like
windows and the Macintosh OS,
provide a graphical user interface
A GUI lets you control the system by
using a mouse to click graphical
object on screen.
A GUI is based on desktop metaphor.
Graphical object appear on a
background (the desktop),
representing resources you can use.
In GUI, icons are pictures that
represent computer resources.
In a GUI, each program opens and
runs in a separate window-a frame
that present the program and its
In a command line interface, you
type commands at a prompt.
Under command line interfaces.
individual applications do not
need to look or function the
same way, so different programs
can look very different.
Very fast small operating
It build into device.
It respond quickly to user input.
This operating system is used
in many devices like, MP3
Players, Medical devices,
Electronic appliances ETC.
One user work on the system.
It perform task at a time.
It take up little space on disk.
It run on inexpensive computer.
Examples are MS-DOS AND PALM-
User perform many tasks at once.
Most common form of operating
Required expensive computers.
Tend to be computer.
Examples are WINDOWS,
Many user connect to one
Each user has a unique session.
Maintenance can be easy.
Require a powerful computer.
Examples are UNIX, LINUX ETC.
In the early 1980’s, Microsoft got the right to
QDOS(Quick and Dirty Operating system)
developed by small company. Microsoft
licenses a version called PC-DOS to IBM and
its version , MS-DOS to other PC
DOS is the most popular microcomputer
It runs thousands of applications.
DOS does not require an expensive computer
DOS has direct access to 640 kilobytes of
DOS is a single tasking operating system.
DOS has character face interface.
UNIX was originally developed in 1969 by
K.Thompson, R.Canaday and D.Ritchie for
minicomputers. By the mid-1970’s, UNIX had been
introduced to University of California at Berkeley by
It is a multiuser, multitasking operating system that
runs on many different computer systems from
micro to main frame.
UNIX is written in C programming language.
UNIX allows users to run multiple programs
simultaneously, UNIX also share it among different
UNIX can be connected through several different
kinds of equipment. It can share files among them.
Limited application program is the disadvantage of
There is not a standard GUI for many UNIX’s.
An application program is written for one version of
UNIX may not run on other versions.
Linux is a free version of UNIX, and its
continual improvement results from the
efforts of tens of thousands of volunteer
It is a open source software-meaning any
programmer can download it from the
internet for free and modify it with
LINUX is more reliable than Windows for
Runs on a wide range of hardware.
Has largest number of user interface
Can be used as server or desktop PC-
Limited commercial applications available.
Can be difficult to learn.
The operating system for Apple’s
Macintosh line of computer systems.
It uses graphical user interface.
It has a hierarchical file system.
Ease of use and learn.
It has a great video architecture that
allows users to add multiple monitors
to a computer.
It enables user to do multitasking.
It provide a high quality graphics
processing for desktop publishing.
It is incompatible with DOS and
This is a graphic based operating
system from Microsoft.
In this windows user can run DOS
applications and change data
It allows cooperative multitasking
A graphical user interface-GUI.
Windows 3.x is not very efficient in
network environment although it
has a network version.
The operating system that succeeded the
combination of DOS with Windows. Two versions
are Windows 95 and Windows 98.
It offers better preemptive multitasking.
It provide plug and play support.
It provide compatibility with existing DOS device
It works as standalone computer and in network
This is easier to use and learn.
It has integrates applications better, connects
Windows 98 adds web browsing capabilities.
It has support larger disks, support DVD’S an
Windows 9X is a mix of 16 and 32 bit application
Windows 2000 combines the user
friendly interface and features of
windows 98 with the file system.
It has networking power and
stability of windows NT.
Some new and improved features
this combination of features
makes windows 2000 both
powerful and easy to use.
Client side operating system introduces in 2001.
It combines elements of windows networking
software and windows ME with a new GUI.
It has improved stability and increased driver and
Windows XP home edition is for typical home
Windows XP professional is for business of all
sizes and for home users.
It also has new features such as built-in instant
It runs on a wide range of hardware.
It has many built-in utilities.
Have to reboot every time a network configuration
It has not efficient used as server operating
Here's everything that's improved in
the Windows 7 UI.
Win 7 kept the glassy Aero desktop
from Vista, but added many more
usability improvements on top of it.
It has improved boot performance. It
has improved performance on multi-
It helps users interact with any
compatible device connected to a
Windows 7 computer; view device
status and run common tasks from a
It enables users to quickly and easily
create home networks between
computers using Windows 7.
Windows 8 features a new user interface based
on Microsoft’s metro design language similar to
that in windows phone.
The new interface is design to better suit touch
screen input along with traditional mouse and
Many Windows 8 programs will be easy-to-use
apps like those found on smartphones and
Windows 8 is tightly integrated with a variety of
Internet-based services, like Facebook, Twitter,
and Microsoft’s SkyDrive online data storage
There are two ways to multitask in Windows 8.
One is the traditional method. This means all your
open programs are accessible from the task bar.
But this works only in Desktop mode. If you want
to multitask in Modern UI mode, you are limited to
seeing two windows at a time
A network operating system is an operating
system that is design to run on a network
server dedicated to providing various
services to other computers on the
network. The other computers are called
client computers. And each computer that
connect to a network server designed to
request a specific service.
Windows NT has support for network
services useful to applications like
client/server database engines.
Windows NT has performs excellently as a
It has a familiar Windows 3.x style user
interface, so users do not need to spend
much for learning.
It has a multitasking capability.
It has much more reliable networking
capability than that provided by windows 3.x
or windows 9X.
Windows NT is a multi-user system, which
means that depending on the user who is
connected to the system, the interface might
VERSIONS MARKET NAME
NT 3.1 Windows NT 3.1
NT 3.5 Windows NT 3.5
NT 3.51 Windows NT 3.51
NT 4.0 Windows NT 4.0
NT 5.0 Windows 2000
NT 5.1 Windows XP
NT 5.2 Windows XP, Windows 2003 server
NT 6.0 Windows VISTA, Windows server 2008
NT 6.1 Windows 7, Windows server 2008 R2
NT 6.2 Windows 8, Windows server 2012