Basic of Computer,What is software?

SOFTWARE

As you are aware, computer cannot do anything on its own. It is

the user who instructs computer; what to do, how to do and when

to do. In order to perform any task, you have to give a set of

instructions in a particular sequence to the computer. These sets

of instructions are called Programs. Software refers to a set of

programs that makes the hardware perform a particular set of

tasks in particular order. Software can be classified mainly

into following categories and sub-categories are shown in

Classification of Software

System Software Application Software

Generalized

Packages

Customized

Packages

Utilities

Operating System

System Software

When you switch on the computer the programs stored in ROM

are executed which activates different units of your computer and

makes it ready for you to work on it. This set of programs can be

called system software.

System softwares are sets of programs, responsible for running

the computer, controlling various operations of computer

systems and management of computer resources. Operating

System (OS) falls under this category.

An operating system is a system software that provides an

interface for a user to communicate with the computer, manages

hardware devices (disk drives, keyboard, monitor, etc), manages

and maintains disk file systems and supports application

programs. Some popular Operating systems are UNIX, Windows

and Linux.

Although operating system provides all the features users need

to use and maintain their systems, inevitably, they still do not

meet everyone’s expectations. This has led to another type of

system software called "Utilities". These are programs that bridge

the gap between the functionality of an OS and the needs of users.

Utility programs are a broad category of software such as

compress (zip)/uncompress (unzip) files software, anti virus

software, split and join files software, etc.

Application Software

Application software is a set of programs, which are written to

perform specific tasks, for example: An application package for

managing library known as library information system is used

to manage information of library such as: keeping book details,

account holder details, book issue details, book return details

etc. Another application package for managing student details is

called student’s information system, manages student’s roll no,

name, parents name, address, class, section, processing of

examination results etc. Application software can be broadly

classified into two types:

(a) Generalized packages

(b) Customized packages

Generalized Packages

These are user friendly softwares written to cater to user’s very

general needs such as preparing documents, drawing pictures,

database to manage data/information, preparing presentations,

play games etc.

It is a group of programs that provide general purpose tools to

solve specific problems. Some of the generalized packages are

listed below:

l Word Processing Software(for preparing documents): Word

Perfect, MS-Word, OpenOffice.org Writer

l Spreadsheets (Data Analysis): Lotus Smart suites, MSExcel,

OpenOffice.org Calc, Apple Numbers

l Presentations : Presentation Graphics, MS-PowerPoint,

OpenOffice.org Impress

Database Management System:

MS-Access, OpenOffice.org Base,

MS-SQL Server, ORACLE

Graphics Tools: Paint shop pro, Adobe Photoshop

Customized Packages

These are the applications that are customized (or developed) to

meet the specific requirements of an organization/institution. For

Example: Student information details, Payroll packages,

inventory control etc.

These packages are developed using high-level computer

language.

COMPUTER LANGUAGES

Languages are a means of communication. Normally people

interact with each other through a language. On the same pattern,

communication with computers is carried out through a

language. This language is understood both by user and the

machine. Just as every language like English, Hindi has its

grammatical rules; every computer language is bound by rules

known as SYNTAX of that language. The user is bound by that

syntax while communicating with the computer system.

Computer languages are broadly classified as:

1. Low Level Language:

The term low level means closeness to the way in which machine

understand. The low level languages are:

a. Machine Language:

This is the language (in the form of 0’s and 1’s, called binary

numbers) understood directly by the computer. It is machine

dependent. It is difficult to learn and even more difficult to write

programs.

b. Assembly Language:

This is the language where the machine codes comprising of 0’s

and 1’s are substituted by symbolic codes (called mnemonics)

to improve their understanding. It is the first step to improve

programming structure.

Assembly language programming is simpler and less time

consuming than machine level programming, it is easier to locate

and correct errors in assembly language than in machine

language programs. It is also machine dependent. Programmers

must have knowledge of the machine on which the program will

run.

2. High Level Language

You know that low level language requires extensive knowledge

of the hardware since it is machine dependent. To overcome the

limitation, high level language has been evolved which uses

normal English like, easy to understand statements to solve any

problem. Higher level languages are computer independent and

programming becomes quite easy and simple.

Various high level languages are given below:

BASIC (Beginners All Purpose Symbolic Instruction Code):

It is widely used, easy to learn general purpose language.

Mainly used in microcomputers in earlier days.

COBOL (Common Business Oriented language): A

standardized language used for commercial applications.

FORTRAN (Formula Translation): Developed for solving

mathematical and scientific problems. One of the most

popular languages among scientific community.

C: Structured Programming Language used for all purpose

such as scientific application, commercial application,

developing games etc.

C++: Popular object oriented programming language, used

for general purpose.

COMPILER AND ASSEMBLER

As you know that High Level language is machine independent

and assembly language though it is machine dependent yet

mnemonics that are being used to represent instructions are not

directly understandable by machine. Hence to make the machine

understand the instructions provided by both the languages,

Compiler and Assembler are required to convert these

instructions into machine language.

The software (set of programs) that reads a program written in high

level language and translates it into an equivalent program in

machine language is called as Compiler.

The program written by the programmer in high level language

is called source program and the program generated by the

compiler after translation is called as object program.

The software (set of programs) that reads a program written in

assembly language and translates it into an equivalent program

in machine language is called as Assembler.