Lecture # 3

Computer Software

Computer Software

“A set of instructions given to the computer to solve user problems

and to control different operations of the computer.”

What is a software?

- The instructions needed to direct the computer to complete specific tasks.

- Software can be categorized broadly into two types :-

Computer Software

The Programs that are on the disks are software

• The Computer software is classified into three main categories:

–Application software–System software–Utility software

COMPUTER SOFTWARE

Application Software

Application Software consists of programs that tell a computer how to produce information. Some of the more commonly used packages are: • Word processing • Electronic spreadsheet• Database • Presentation graphics

Word Processing• Word Processing software is used to create and print

documents. A key advantage of word processing software is that users easily can make changes in documents.

Electronic Spreadsheets• Electronic spreadsheet software allows the user to add,

subtract, and perform user-defined calculations on rows and columns of numbers. These numbers can be changed and the spreadsheet quickly recalculates the new results.

Database Software• Allows the user to enter, retrieve, and update data in an

organized and efficient manner, with flexible inquiry and reporting capabilities.

Presentation graphic software• Allows the user to create documents called slides to be

used in making the presentations.

APPLICATIONS

• MS Internet Explorer• (Your internet

Browser)

TYPES OF BROWSERS

Mozilla Firefox Internet Explorer Opera Safari Konqueror Flock

Firefox is gaining Popularity over IE

Flock

System Software: System Software includes the Operating System and all the

utilities that enable the computer to function.

System software is a term referring to any computer software which manages and controls the hardware so that application software can perform a task.

Example: Operating Systems, Compiler, Disk Drivers etc.

Definition of OS :-A set of programs that control and

supervise a computer system’s hardware

Purposes of OS :-• To manage the hardware for efficient

utilization of computer resources

• To interface between a user/an application program with the hardware

Operating System

• OS is made up of 2 programs;

Control Program

Service Program

Operating System

1. Control program - three main functions

Resource allocation

allocate processor time, primary storage, input and output devices

Job management

to monitor, schedule and control programs for its efficient processing

Data management

-managing access to data for input of information to printers, disks/displays- all hardware components activities are controlled by the supervisor program

Operating System

2. Service programs- provides services to the user/programmer- services include language-translator programs and utility programs- language-translator program converts instructions from English-like language to machine-language to be executed by the computer- utility program performs loading, saving, copying, keeping track of files stored on a disk, preparing a formatted disk

Operating System

Language TranslatorUtility

Progra

m

Other Services

Data Mgmt.Job

Mgmt.

Resource Allocation

Supervisor

Operating System

TYPES OF OS

Microsoft Windows (98, 2000, XP, Vista, 7, 8)

Mac OS (X) Linux OS (Hundreds of

even thousands of distros ex: Red Hat, Ubuntu, Mandrake etc. Visit http://distrowatch.com/ for listing of Linux OS)

Unix OS etc.

OPERATING SYSTEMS

• MS-DOS• Windows 95,98,Me• Windows NT,

2000,XP,7,8

• Red -hat Linux, Ubuntu, Centos, Fedora, Mint

System Software

Device Driver• A program that controls a particular type of device

that is attached to your computer.

• There are device drivers for printers, scanner, modem, displays, CD-ROM and so on.

• A device driver essentially converts the more general input/output instructions of the operating system to messages that the device type can understand.

• Also known as service routine, utility software helps to analyze, configure, optimize and maintain the computer.

• Examples:– Disk Defragmenters – Systems Utilities– Antivirus Scanners– Disk Cleanser

Utility Software

Thank You