This document discusses different types of computer software. It defines software and describes system software and application software. It provides details on operating systems, their functions, and examples. It also discusses utility programs and device drivers. The key points are that software provides instructions to computers, system software manages hardware and allows execution of application software, and operating systems control overall computer operation and interface between hardware and users.

1. Computer Software

2. Introduction
 A set of instructions given to the computer to solve a
particular problem is called software
 Also called computer program
 Software tells the computer what to do and how to
do
 Hardware operates under the control of given set of
instructions
 Software is developed in computer programming
language

3. Types of Software
 System Software
 Application Software

4. Application Software
 A program or set of programs that are specially
designed to solve the specific problem of users
 Different kinds of application software
 Commercial software, scientific software, financial
packages, games, multimedia etc
 Two main categories
 Custom built software
 Packaged Software

5. Custom-Built Software
 Developed for a particular organization or customer
 Also known as customize software
 For example, software developed to maintain the records
of students of a particular college

6. Packaged Software
 Developed by software development organization
for sale to the general public
 Used to solve some common problems of many
people or users
 Examples
 Word Processing Software
 Spreadsheet Software
 Database Management Software
 Communication Software
 Presentation Software
 Graphics Software

7. Examples of Graphics Software
 Computer Aided Design
 Desktop Publishing
 Painting Software
 Image Editing Software
 Video & Audio editing Software
 Web Page Authoring Software

8. System Software
 A program or set of programs that is specially
designed to control different operations of the
computer system
 Controls the working of different parts of the
computer
 Enables the other application programs to execute
properly
 Examples:
 Operating Systems
 Utility Programs
 Device Drivers
 Language Processors

9. Operating System
 An operating system is a collection of system
programs that controls and coordinates the overall
operation of the computer system
 Also provide the interface between the user and the
computer system
 A computer needs an operating system to do work

10. Tasks of Operating System
 Accepts input from input devices
 Sends output to the output devices
 Manages the application program in memory
 Manages the files on the storage devices
 Manages & controls the I/O devices

11. Operating System
https://en.wikipedia.org/wiki/Process_management_(computing)

12. Parts of Operating System
 Resident Part
 Also known as kernel
 Contains the critical functions
 Loaded into the main memory during the booting process
of computer
 Non-Resident Part
 Loaded into the main memory when required

13. Examples of Operating System
 Disk Operating System developed by Microsoft
 Operating System 2 developed by IBM
 XENIX developed by Microsoft
 Windows developed by Microsoft

14. Operating System Functions
 When computer is turned on the operating system is
loaded into the main memory from the disk
 Most of the operating systems perform the similar
functions

15. Operating System Functions
 Booting a Computer
 User-Interface
 Running Programs
 Managing Files
 Memory Management
 Scheduling Jobs
 Configuring Devices
 Establishing Internet Connection
 Controlling Network
 Task Management

16. Booting a Computer
 The operating system consists of supervisor portion
and a set of system programs
 When the computer is switched on, the supervisor
portion of the operating system is loaded in the
RAM from the disk
 The process to start or restart a computer is called
booting process
 Two Types
 Cold boot
 Warm Boot

17. User Interface
 User interface means how the user interacts with the
computer to perform various tasks
 User runs the application programs, open the
documents, enters the data, print the output report
 The operating system plays the main role for
interfacing between user and computer
 The hardware devices like keyboard, mouse,
monitor are used for interfacing
 Two main types of user interface
 Command Line User Interface
 Graphical User Interface

18. Running Programs
 The operating system also provides the interface
between the programs and the user
 Through program, the user access other computer
resources
 There is built in instruction in program known as
“system calls” that are used to request the services
from the operating system
 The application program sends the request to the
operating system and the operating system gives the
result back to the program

19. Running Programs
 Saving the data from memory in files on the disk
 Loading the files from disk into memory
 Sending the document on the printer
 To copy or move the data from one document to
another
 For the services of hardware
 To prepare the disk to store data etc

20. Managing Files
 The data and programs are stored permanently on
the disk for future use
 The files are stored on the disk by giving a file name
 The files are placed or stored in folders or
directories
 A folder may contain file or sub folders
 The operating system maintain a list of these files
and folders in the staring area of the disk called FAT
 File Viewer utility program is used the names of
files and sub folders
 For Example, Windows Explorer

21. Memory Management
 Memory unit has very important role for data
processing
 Processor takes data and instructions from RAM
during processing
 The operating system loads the data and programs
into RAM and allocates the memory areas and
manage these properly
 When the program is closed, the operating system
clears the memory area allocated to that program
and its data

22. Memory Management
 During data processing some operating system use
the hard disk as memory, called virtual memory
 During processing, operating system transfer some
of data from RAM to hard disk and reload when
required, called swapping
 Operating systems spends a lot of time in paging
process, instead of executing the application
software, it is referred to as Thrashing

23. Scheduling Jobs
 A job is an activity or operation that a processor
performs
 May be receiving data from input device
 Sending output to the output device
 Loading data from disk into RAM
 Operating system determines the order in which
jobs are to be processed
 First Come First Serve Basis
 Priority Basis
 If there are multiple jobs of the same nature, the
operating system place the request in buffer,
temporary, process called spooling

24. Configuring Devices
 The functions of devices attached with the computer
are controlled by the special system software called
device drivers
 Device driver tells the operating system how to
communicate with a device
 Each device has its own device driver
 When you boot a computer, the operating system
loads each device driver
 Usually the operating system has built-in device
driver for commonly used input/output devices
 Operating system automatically install these driver

25. Establishing Internet Connection
 Operating System provides means to establish
connection between your computer and the ISP
(Internet Service Provider) server
 Some Operating System have built-in program used
to access the information on the internet
 Information downloaded from the internet is
managed by the operating system in RAM as well as
in disk

26. Controlling Network
 Some operating system are specially developed for
networking
 Called Network Operating System (NOS)
 A network operating system organizes and
coordinates multiple users and make it possible to
access and share resources on network
 Overall functions of users are controlled by NOS
 Creation of account of new user
 Deletion of user account if required
 NOS also has security features
 Require a user name and password to access the network

27. Task Management
 A task is an operating such as storing, printing,
calculating etc
 A computer can perform many tasks at a time
 Some operating system can handle more than one
program at the same time
 The operating system manage all these tasks
 Some operating system have single user
functionality and can support only one user at a time

28. Task Management
 The operating system performs the following tasks:
 Multi Tasking
 Multi Programming
 Multiprocessing
 Time Sharing
 Multithreading
 Virtual Memory
 Spooling

29. Types of Operating System
 In the past, operating system were computer
dependent
 An operating system running on one machine could
not be run another different type of machine
 Three basic categories of operating system are:
 Personal Computer Operating System
 Network Operating System
 Embedded Operating System

30. Personal Computer Operating System
 Also called stand alone operating system or single
user operating system
 Used to operate personal computers
 Examples
 DOS
 Mac OS
 Windows

31. Network Operating System
 Supports the network
 Typically resides on a server and controls the
devices or computers connected to the network
 Examples:
 Windows NT Server
 Windows 2000 Server
 UNIX
 Solaris
 Novell’ s Netware

32. Embedded Operating System
 Different special electronic devices and handheld
computers are also controlled by the operating
systems that are stored in the ROM chip
 Examples:
 Windows CE
 Pocket PC 2002
 Palm Operating System

33. Difference between Windows & DOS
 DOS provides command line Interface, while
Windows provides Graphical User Interface
 DOS is single tasking operating system, While
Windows is multi-tasking operating system
 DOS does not provide plug and play feature, while
Windows provide plug and play feature

34. Utility Programs
 A software that helps the user to solve the specific
problems related to the software and hardware is
called utility programs
 It is system software
 A large number of utility programs are available for
the service of hardware and software
 Most operating system include various utility
programs
 While others are available on CDs or can be downloaded from the
internet

35. Utility Programs
 File Viewer
 File Compression
 Diagnostic Utility Program
 Un-Installer
 Disk Scanner
 Disk Defragmenter
 Back up Utility

36. Device Drivers
 The programs that operate and control the devices
attached to the computer are called device drivers
 The keyboard, mouse, disk driver, CD-ROM drive,
Modem, Printer etc require to install software that
tells the computer how to use the device
 When you purchase a new hardware device,
manufacturer of the device also provides you a disk
containing a device driver