OPERATING SYSTEM AND

1 GRAPHICAL USER INTERFACE

ROLES AND FUNCTIONS
Sratoh LEARNER'S OUTCOMES
After completing this chapter, you will be able to:
know the types of software define an operating system
understand the need for an operating system list the functions of an operating system
list the types of operating systems
INTRODUCTION
A computer is an electronic device that performs a specific task according to the given
instructions. A computer system has two components:a and software. Both
have equal importance.
Hardware refers to the physical parts of a computer that we see and touch.
§ Software refers to the instructions that tell the hardware what to do.
Hardware and software cannot perform any task without each other. The
combination of both becomes a system.
TYPES OF SOFTWARE
The instructions given to the computer in the form of a program is called software. A
program is a sequence of instructions, written to solve a particular problem and make
the hardware perform a specific task.
Software is classified into two types, depending on their functions and the
requirementsof auser. These are:
System Software
Application Software
System Software
The system software instructs a program that interacts with the hardware. It manages
the operations of asystem. It directs the computer what to do, when to do and bow to
do. It acts as an interface between the user and the hardware.
Functions of the system software are:
Reading data Translating data
Controlling data Processing and generating output

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System software can be classified as:
Operating system Language processor
Device driver Utility software
Application Software
Application software is a set of programs, used to perform specific tasks like creating a
document, presentation or a database, for example, Microsoft Word, Microsoft
PowerPoint, Microsoft Excel.
OPERATING SYSTEM
The computer, being a machine, cannot perform any task on its own. It requires
instructionsto do a specific task. These instructions are given by the user in the form of
programs. Basically, an operating system is a set of programs that is used to operate a
system.
It acts as a platform for the computer hardware and the user. It
coordinates the
activities of a computer and also sharing of resources.
Every computer must have an operating system to run other
DOS, UNIX, LINUX and Windows. programs, for example,
Monitor

Applications
Printer

(Operating
System
Hard Drive
Mouse

Keyboard
An operating system is an essential component of the
system software, Almost
everyone nowadays uses mobile phones, playing games or uses specific
mobile phones, we need an interface between mobile phones and us. apps. To use
This interface is
called operating system.
An operating system encompasses all operationssuch as:
What to do? When to do?
Howto do?
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 NEED FOR OPERATING SYSTEM
An operating system occupies the prime position between the hardware and the user.
The user interacts with the system through the operating system. An operating system
is, therefore, needed to create a link between the hardware resources, the user and the
applications.
The operating system works in the background and acts as a host for other application
software, helping them run over the operating system. It provides a variety of services
to yourcomputer through system calls. It is the operating system that coordinates and
helps you use the external devices (like mouse, keyboard) that are connected to your
computer.
The operating system also manages the files and folders stored in the computer. Hence,
it is also called the Resource Allocator Deallocator as it manages all the resources like
I/Odevices, memory space, information and the central processor.
You also work with the operating system directly. There are special commands that can
be given to it. You do not need an application software to use your computer. An
operating system interprets and executes allthe commands given directly or indirectly
to it. Meanwhile, it also controls and monitors the functioning of the application
programs that are exeCuted on it.
FUNCTIONS OFOPERATING SYSTEM

An operating system provides a variety of services Program

Execution
File
Management
to acomputer and its users. Some major functions
of an operating system are: Operating
System
1. Program Execution: It receives the commands
Memory
from any application or a system program, Device
Management Management
interprets it and then executes it.
2. Device Management: Allocation and de-allocation of all input and output devices
are done by the operating system. It controls the working of all the devices
connected to your computer.
allocates
3. File Management: It helps you to organise all the data in files/folders and
space forfiles on secondary storage devices when required. It keeps the track of the
location of every file on the disk.
Memory Management: Memory is a major part of the computer system. It dictates
the speed of the operations. Thus, the main memory is managed by the operating
SVstem, to ensure the efficient functioning ofyour computer system.
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 TYPES OF OPERATING SYSTEM
Operating system is classified into the following type. This classification is based on
the capabilityof processing.
$ Single-user operating system: It is used on a single computer to perform a single
task. It performs one task at a time. MS-DOS is an example of a single-user
operating system.
¢ Multi-user operating system: It allows the same data and application to be used by
multiple users at the same time. The users also communicate with each other. Some
operating systems, that fall in this category are LINUX and UNIX.
$ Multiprocessing operating system: It consists of several processors for a single
running process. It allows the user to run and work on multiple applications at the
same time. Since execution- takes place in parallel, it is used for high-speed
execution, for example: LINUX, UNIX and Windows 7.
Real-time operating system: It is designed to control machines such as guided
missiles, nuclear reactors and online ticket reservation system. It is a
multi-tasking
operating system that requires to work under defined time constraints. The real
time operating system depends on the time in which the results are produced and
on the logical results of the computation.
Distributed operating system: It is used on anetwork as it allows the shared data
to be accessed from any machine on the network. It
controls these interconnected
systems and makes them appear on a single computer.
& Interactive operating system: It provides a GUI (Graphical User
which the user can easily navigate. The computer responds very
Interface) through
fast, almost
immediately, after an instruction has been entered. It is a user-friendly operating systen.
Some commonly used operating systems:
1. Windows: It is a GUI system. Various
versions of Windows are Windows 95,
Windows 98, Windows7, Windows 8 and Windows 10.
2. UNIX: It is amultitasking, multi-user operating
system. It was developed in 1969.
3. LINUX: It is a free and open source
software, which means it is freely available
for use.
A Solaris: It isa free UNIX based
operating system introduced by Sun Microsystems
in 1992.
5 Mobile Operating 5ystem: ltoperates on digital mobile
ablets.It incudes Bluetooth, WiFi, mobile devices like smartphones
navigations and more.
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 O uSER INTERFACE
Interface is the platform where two systems interact with each other. As computer is
the hardware (machine) that cannot perform any task without
instructions, it is the
User who gives instructions to the computer. The question is how to give
instructions?
The user interface is a program that controls the display and allows the user to
interact
with the system.
Types Of User Interface
There are two types of user interface: CUIand GUI.
1. Character User Interface (CUI): This type of operating system requires the users to
interact with the system by typing the commands. Unix and DOS are the CæI based
operating systems. CUlis also known as CLI: Command Line Interface.

DOS
QDo You Know
Microsoft's first operating system, DOS 1.0, was launched in August 1981.
Android is an operating system for mobile phones.

2. Graphical User Interface (GUI): This is popularly known as GUI as the look of the
operating system is graphic oriented. The user uses a mouse to interact with the
system. If you have a touchscreen computer, you use touch gestures (liketap, press
and hold, pinch, swipe, scrollor rotate) to interact with the system. Such operating
systems are more popular than CUI, due to their ease of use. Windows and Linux
are the most popular GUI based operating systems.

Oypo hero to seach

Windows 8.1 Windows 10

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 Do You Know
Windows 1.0 was launched by Microsoft in November 1985.
Difference Between CçI And GUI
Character User Interface Graphical User Interface
CUlstands for Character User Interface. GUIstands for Graphical User Interface.
MS DOS is characterised as CUl. § Windows is characterised as GUI.
o A CUI uses characters on the screen that
are A GUI uses pictures, graphics and icons that
controlled with the keyboard. are controlled with the mouse.
Only one application runs at a time. § Number of applications open and are
The syntax and various options are executed
required indifferent windows at the same time.
to be remembered. § No need to remember the commands as it is
user-friendly.
Key Points
The combination of hardware and software
makes a system.
Software two types: System Software and Application Software.
is of
An operating system isa set of programs, that is used to
operate a computer.
Interface is theplatform where two systemsinteract witheach other.
CUI and GUlare the tWo types of user interface.

EXERCISES
Multiple Choice Questions
Section-A O0
1. Which of the following is an application software?
(a) Unix (b) Photoshop (c) MSDOS
2. The
.operatingsystem operateson digital mobile devices.
(a) Windows (b) Mobile | (c) Tablet
3. . is a hardware device.
(a) Mouse
| b ) Solaris (c) LINUX
4. is Microsoft's first
operating system.
(a) Windows 1.0 (b) Windows 11
(c) DOS1.0

10 Computers-8
 Fill in the blanks.
1. user interface is more user- friendly.
2.
is a free UNIX based operating system introduced by Sun Microsystems.
3. The
operating system allows auser to run and work on multiple applications at
the samne time.
4.
.software is aset of programs used to perform specific tasks.
Write T for true and F for false statements.
1. GUIuses characters on the screen that are controlled with the keyboard.
2. An operating system is a set of programs, that is used to operate the system. O000
3. Software isof three types.
4. TheSystem Software instructs aprogram that interactswith the hardware.

Section-B
A Answer the following.
1. Why do we need an operating system?
2. Define hardware and software.
3. What isa system software?
4. List the functionsof an operating system and explain them.
5. List the types of operating system and explain them.
6. Differentiate.between CUIand GUI.
B Computer In Everyday Life (Application-based Question)
Aocording to Mridul, mobile phones do not require any operating system. Do you.agree with
him? If not, give examples of operating systems for mobile phones.

FUN ZONE
ACTIVITY
Prepare areport on operating systems mentioning commonly used computer operating systems
and mobile operating systems with their latest versions.

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