Software: Software is one of the primary elements of a computer system. It is a set of computer programs, procedures and associated documentation related to the effective operation of a computer system. The software’s are classified into the following categories:

1. System Software

2. Utility Software

3. Application Software

1. System Software: System software is programs that directly interact with the hardware. For example, when a file is to be saved on a disk, the system software sends the required instructions to perform this task. It provides the environment to write application programs. The system software is written by computer professionals called System Programmers.

The system software is of two types:

Translators

Operating System

Translators: Instructions given to a computer in any language, have to be translated into machine code for the computer systems to execute the instructions. This work of translation is done by a Translator.

Translators can be classified as:

Interpreters

Compilers

Assemblers.

(a) Interpreters: Interpreters are the translators which are used to convert programming language into machine language for the purpose of execution line by line. It translates one statement at a time and executes it.

(b) Compilers: The compiler translates the whole program code (known as source code) and prints a list of errors which have to be corrected as a whole. Once the program is error-free, the executable code is generated.

(c) Assemblers: This software translates a program written in assembly language to machine code.

(ii) Operating System: An Operating System is a set of routine programs that are used to manage the operations of the computer. The Operating System isolates the hardware from the user. The user communicates with the Operating System, supplies application programs and the data that are in a language and format acceptable to the Operating System and receives output. Some of the popular operating systems are:

DOS, WINDOWS 95, WINDOWS 98, WINDOWS NT, WINDOWS Millennium, XP, OS/2, LINUX, UNIX.

2. Utility Software: A utility program is a type of system software that performs a specific task, usually related to managing a computer, its devices or its programs. Most operating systems include several utility programs. Some of the utilities are described below:

(i) File Compression Utility: A file compression utility reduces or compresses the size of a file. A compressed file takes up less storage space on a hard disk or floppy disk, which frees up room on the disk and improves system performance. When a compressed file is received, it must be uncompressed or unzipped to restore it to its original form. Two popular stand-alone file compression utilities are PKZIP and WinZip.Disk Scanner: A Disk Scanner is a utility that detects and corrects both physical and logical problems on a hard disk or floppy disk. It also searches and removes unwanted files. Windows 98/XP includes two disk scanner utilities:

Scan Disk which detects and corrects problems.

Disk Cleanup searches for and removes unnecessary files such as temporary files.

(ii) Disk Defragmenter: A disk defragmenter is a utility that reorganizes the files and unused space on a computer’s hard disk so that data can be accessed more quickly and programs can run faster. When a computer stores data on a disk, it places the data in the first available sector on the disk. Disk defragmenter reorganises the file and unused space. Windows includes a disk defragmenter called Disk Defragmenter.

(iii) Uninstaller: An uninstaller is a utility that removes an application, as well as any associated entries in the system files. When you install an application, the operating system records the information that it uses to run the software in the system files. If you attempt to remove the application from your computer by deleting the files and folders associated with that program without running the uninstaller, the system file entries remain.

(iv) Anti-virus: An anti-virus program is a utility that prevents v detects and removes viruses from a computer’s memory or storage devices. A virus is a program that copies itself into other programs and spreads through multiple computers. Viruses are designed to damage a computer intentionally by destroying or corrupting their data.

(v) Back-Up: This is used to back-up files on your hard disk. Files can be back-up to a floppy disk, a tape drive or another computer on the network. If the original files are damaged or lost, it can be restored from the backup.

(vi) Search Engine: It is used to search files or data from the disk quickly. It works randomly to give search results to the user as quickly as possible.

3. Application Software: Application software consists of programs designed to perform specific tasks for users. Application software also called a software application, can be used for the following purposes:

As a productivity/business tool.

To assist with graphics and multimedia projects.

To support household activities, for personal business, or for education.

To facilitate communications.

Word Processor: Word Processor transforms a screen into ‘sheets of paper’ to be written on, and provides quick and accurate ways to create and revise business documents. These packages allow: Text to be written in document form. Edit any part of a document. Adjust the format of a document, such as margins, spacing, page numbers. Save the entire document on a disk and retrieve it later. Example: Wordstar, MS-Word, Word Perfect, Page Maker.

Spreadsheets: A spreadsheet is a table consisting of rows and columns, and provides business professionals with a quick and accurate means of performing mathematical calculations involved in answering a question. It performs various mathematical functions as well as logical and conditional operations in a quick and accurate manner. Examples: Lotus 1-2-3, Quattro Pro, Excel, Multiplan. 

Database Management System: Database Management System (DBMS) is a set of programs that manipulates a database by appending, deleting and modifying records. It is used to generate the queries, forms, reports etc. on the basis of some condition by using different records stored in it.

The two basic types of data management software are File management systems, for example, Dbase, Foxbase, FoxPro etc.

Relational Database Management System, for example, Ingress, Oracle, Unify etc.

Graphics/Presentation Packages: This software is used to create slide transition, animation, etc. by using its advanced features. Most of the graphics or presentations are being prepared using this software. PowerPoint, Corel Draw, Macromedia, Director.

Desk Top Publishing (DTP) Software: It is a software system that is used to produce attractive page layouts complete with pictures and text printed in a variety of styles, which is ideal for use in newspaper and magazine publishing companies. Examples: Page Maker, Word, Corel Draw.