Notes on Software and Classification | Grade 11 > Computer Science > Computer System | KULLABS.COM

Software and Classification

CoVID-19 EG Scholarship

Notes, Exercises, Videos, Tests and Things to Remember on Software and Classification

Please scroll down to get to the study materials.

Registration open for Special Scholarships

  • Note
  • Things to remember


A software is a means of communication between the computer system and computer users. It is the operating system and applications that are used in computers. Basically, it is the collection of computer programs, documentation and procedures performing several tasks on a computer system. Thus, it is considered to be the heart of computer systems.



Generally, computer software consists of a machine language consisting of groups of binary values, specifying the processor instructions. The instructions change the state of computer hardware in a sequence that is pre-determined. In conclusion, a computer system is a language in which a computer speaks. There are 2 types of computer software. They are:

1.) System Software:

It is a collection of operating system, servers, device drivers, utilities and windows systems which helps in running the computer hardware and the computer system. It is designed to provide a platform to run application software and operate the computer hardware.
This software helps an application programmer to view away memory, hardware and other internal complexities of a computer. Some of its common types are:

i) Operating system:

From performing basic tasks to running important programs, the operating system is the most important program to run a computer. It is the 1st program that loads into memory when the computer is turned on. Without the operating system, no other programs such as spreadsheet software, word processing software, etc. can be run. So, in a sense, this system brings the computer to life.

When given a command, the operating system issues the instructions to the ‘brain’ i.e. the CPU or microprocessor. While working on the application software, such as Microsoft Word, your given commands are sent through the operating system to the CPU. Some of its examples are Windows2000, Windows95/98, DOS, UNIX, Mac OS, etc. Below are some of its functions.

  • Provide security and backup.
  • Booting computers.
  • Controlling peripheral devices such as a keyboard, disk drives, printers, etc.
  • Provide interface between software and hardware.
  • Scheduling processes.
  • Memory management.
  • Keeping track of files and directories on the disk.
  • Recognize input from the keyboard.
  • Send output to the display screen.

ii) Utility Software:

Utility software are set of collective programs, available to help you with the day to day chores that are associated with personal computing and to keep your computer system run at peak performance. These are designed to help manage, control and maintain computer resources.

Some examples of utility software are:

  • Virus scanning Software / Antivirus: It protects computers from computer viruses.
  • Scandisk: It scans disks for any potential problems on them, such as bad disk areas or any physical error.
  • Backup software: It helps in making copies of your files and even an entire computer hard drive for backup and restoration.
  • Debuggers: These are used mainly to solve programming errors.
  • Disk Defragmenter software: It assists you in reorganizing those disk drives which have been scattered across several hard disk locations while files are saved, deleted and resaved again.
  • File managers: They provide you a convenient method to perform routine data management, management tasks and e-mail recovery.

iii) Language processor:

It is a special kind of computer software which translates the programs written in one language into another language. It is compulsory for both low and high-level language. The types of language translators are:

  1. Compiler
  2. Interpreter
  3. Assembler

2) Application Software:

Application software is used to solve application type of problems. Business software, educational software and databases are some forms of application software. This software enables the users to accomplish certain specific tasks and utilizes the capacities of a computer directly to a dedicated task. It can manipulate numbers, texts and graphics. It can also focus on a certain single task like work processing, spreadsheet or playing of audio and video files. Its types are:

i) Package software:

Package software is for general purposes. Designed by software companies, it is mainly to generalize the tasks. Some common package software are:

Word Processing Software:This software enables the users in creating and editing documents. MS-Word, Notepad, Word pad and some other text editors are some most popular examples of Word Processing Software.

Database Software:It organizes the data and enables the users to achieve database operations. It also allows the users to store and retrieve data from databases. MS Access, Oracle, etc. are its examples.

Spreadsheet Software:By displaying multiple cells that make up a grid, this software simulates paper worksheets and allows the users to perform calculations. Its examples are Apple Numbers, Excel, Lotus 1-2-3, etc.

Multimedia Software:This software allows the users to create and play audio and video media. Audio converters, burners, players, video encoders and decoders are some forms of it. Real Player and Media Player are examples of this software.

Presentation Software:This software is best used to display information in the form of a slide show. It includes 3 functions.

  1. Editing, allowing insertion and formatting of text.
  2. A functionality of executing the slide shows.
  3. Methods to include graphics in the text.

Microsoft Power Point is its best example.

ii) Tailored software:

Tailored Software is also called small type of software. Tailored software is for specific purposes. Written in high-level languages such as C, JAVA, C++, COBOL (Common Business Oriented language), etc. these types of software are developed for a specific task. Banking software, hotel reservation software, hospital software, billing software, etc. are its examples.

Computer Virus

Computer viruses are the programs or malware which are loaded onto your computer by ‘mean’ people, without your knowledge. These viruses replicate relentlessly and infect computer programs. They might even delete or corrupt your computer data or erase your hard disk too. These virus programs are placed into commonly used programs. So, when those programs are run, the attached virus infects the executable program or file.

These viruses are not of same purposes. Some have destructive intents while some are designed to play annoying tricks. Some might present themselves as jokes while doing destructive functions secretly. There are 2 major kinds of viruses. They are:

  1. Compiled Viruses:executed by the operating system.
  2. Interpreted Viruses:executed by an application.

Symptoms of Virus:

  • Slowing down of the speed of the computer.
  • Change in files’ extension.
  • A long time in the loading of a program.
  • Showing of unusual error message on the screen.
  • System data corruption.
  • Memory space reduction in a computer.
  • Inaccessibility to the location of files.

Prevention of Virus:

  • Password protection should be employed.
  • Execute familiar programs only as to their origin. Programs sent by e-mail should always be suspicious.
  • Load software only from original CDs or disks instead of pirated or copied ones.
  • Check all shareware and free programs downloaded from online services with a virus checking program.
  • Computer uploads and “system configuration” changes should be always performed by the computer owner.
  • Purchase or download an anti-virus program that runs as you boot or work on your computer. Also, update it frequently.

Types of Viruses

  1. Trojan Horse: Appearing as a useful and desired function, a Trojan Horse program neither replicates nor copies itself, but causes damages and compromises the security of a computer. This virus program may arrive in the form of software of some sort or a joke program that must send by someone or carried by another program.
  2. Worm: It is a program that copies and facilitates self-distribution from one disk drive to another or by copying itself using e-mail or any other transport mechanism.
  3. Macro Virus: These viruses infect documents such as MS Excel or MS Word and other similar documents. These viruses use another application’s macro programming language to distribute themselves.
  4. Boot sector Virus: Normally, spread by floppy disks, this virus attaches itself to the 1st part of the hard disk which is read by the computer upon boot up.
  5. Polymorphic Virus: A Polymorphic Virus is a very sophisticated virus program as it not only replicates itself by creating multiple files itself but also changes its digital signature each time it replicates.
  6. Memory Resident Virus: This virus is initiated from a virus within the computer and they stay in a computer’s volatile memory (RAM) after its initiating program closes.

Computer Antivirus

An antivirus is a computer software designed to scan, detect and remove viruses and malicious software from computers. This software defends your computer against computer viruses that threaten to infect your computer files and systems. In order to be an effective defense virus, an antivirus needs to run all the times in the background and should be kept updated frequently.

Originally developed for the detection and removal of computer viruses, with the emerge of several kinds of viruses, antivirus software programs started to protect from other computer threats. Antivirus scans the files and folders and alerts the user if viruses are found. Some known and popular antivirus software are Kasper-sky, Avira, Norton, Avast, AVG, etc.

Identification Methods:

  1. Sandbox detection
  2. Data mining techniques
  3. Signature based detection
  4. Rootkit detection
  5. Heuristic detection

(Karn & Pudasaini, 2015)


Karn, M. K., & Pudasaini, D. (2015). Computer Science I. Anamnagar, Kathmandu: Buddha Publication.

Adhikari, Deepak, Computer Science- XI, Asia Publication Pvt. Ltd, ktm

  • Software is the means of communication between the computer system and computer users
  • System software  provides the basic functions for computer usage and helps run the computer hardware and system.
  • Application software is used to solve application type of problems.
  • Computer viruses are the programs or malware which are loaded onto your computer by ‘mean’ people, without your knowledge. 
  • An antivirus is a computer software designed to scan, detect and remove viruses and malicious software from computers. 

Questions and Answers

Click on the questions below to reveal the answers


ASK ANY QUESTION ON Software and Classification

No discussion on this note yet. Be first to comment on this note