SOFTWARE & OPERATING SYSTEM

Software

Software is a collection of computer programs and associated instructions that tells the computer how to perform specific tasks.

Software is often considered the soul of a computer because hardware cannot function without software.

Relationship Between Hardware and Software

• Hardware depends on software for instructions.
• Software requires hardware to execute instructions.
• A computer can perform a task only when it receives the appropriate set of instructions.

Basic Relationship:

User

↓

Software / Instructions

↓

Hardware

↓

Processing and Output

TYPES OF SOFTWARE

Computer software can broadly be classified into:

SOFTWARE

│

┌────────────┴────────────┐

│                         │

SYSTEM SOFTWARE          APPLICATION SOFTWARE

│

┌──────┼──────────┐

│      │          │

OS   Translator  Utility

SYSTEM SOFTWARE

System software is a type of computer program designed to operate and control computer hardware and provide a platform for application software.

Main Functions

• Controls the internal functioning of the computer
• Manages computer hardware
• Helps application programs execute correctly
• Controls peripheral devices such as:
  • Monitors
  • Printers
  • Keyboards
  • Other input and output devices

Examples

• Operating Systems
• Language Translators
• Utility Software

4. OPERATING SYSTEM

An Operating System (OS) is system software that manages computer hardware, software resources and provides common services for computer programs.

It acts as an interface or bridge between the user and the computer hardware.

USER

↕

OPERATING SYSTEM

↕

COMPUTER HARDWARE

Importance of an Operating System

• Manages hardware resources
• Controls the execution of programs
• Makes computers easy to use
• Manages files and folders
• Manages memory
• Controls input and output devices
• Provides security and protection

Without an operating system, it would be difficult for ordinary users to operate a computer.

5. LANGUAGE TRANSLATOR

A language translator or language processor is software that converts a program written in one computer language into another language, especially machine language.

Computer hardware understands machine language, so programs written in assembly or high-level languages must be translated before execution.

Source Program

(Assembly / High-Level Language)

↓

LANGUAGE TRANSLATOR

↓

Machine Language

↓

CPU

Types of Language Translators

1. Assembler

An assembler translates:

Assembly Language → Machine Language

2. Compiler

A compiler translates a high-level language program into machine language.

Important Feature:

A compiler generally translates the entire program at one time.

3. Interpreter

An interpreter translates and executes a high-level language program:

One statement or line at a time

Compiler vs Interpreter

Compiler	Interpreter
Translates the entire program at once	Translates one statement at a time
Reports errors after compilation	Reports errors line by line
Execution is generally faster after compilation	Execution is generally slower
Produces translated code/object code	Generally does not produce a separate object code file

6. UTILITY SOFTWARE

Utility software is system software that helps maintain the proper and smooth functioning of a computer system.

It assists the operating system in:

• Managing the computer
• Organising files
• Maintaining the system
• Optimising performance
• Protecting the system

Common Functions

• Virus detection
• Data backup
• File management
• File compression
• Disk management
• Installation and uninstallation of software
• Deletion of unwanted files

Examples

• Antivirus software
• File management tools
• Compression tools
• Disk management tools
• Backup software

7. APPLICATION SOFTWARE

Application software is software designed to perform specific tasks for the end-user.

Examples

• MS Word → Word processing
• MS Excel → Spreadsheet calculations
• MS PowerPoint → Presentations
• Web browsers → Internet browsing
• Media players → Playing audio and video

Main Features

• Performs specific user-oriented tasks
• Accepts user input
• Helps users complete their work
• Generally operates with the support of system software

Basic Relationship

USER

↓

APPLICATION SOFTWARE

↓

SYSTEM SOFTWARE

↓

HARDWARE

8. WEB-BASED APPLICATION

A web-based application is an application that is accessed through a network, generally using web technologies such as HTTP, and runs through a web server.

Unlike traditional software installed and run locally on a computer, web applications are generally accessed through a web browser.

Examples

• Google Docs
• Google Sheets
• Google Slides
• Cloud storage services

Basic Structure

User

↓

Web Browser

↓

Internet / Network

↓

Web Server

↓

Web Application

9. MOBILE APPLICATION

A mobile application or mobile app is a software application designed to run on mobile devices such as:

• Smartphones
• Tablets
• Smartwatches

Uses

• Communication
• Online banking
• Education
• Entertainment
• File sharing
• Online shopping
• Collaboration

Mobile applications are generally downloaded from platforms such as:

• Google Play Store
• Apple App Store

10. FUNCTIONS OF AN OPERATING SYSTEM

1. Input/Output Management

The operating system manages requests related to input and output operations.

It also loads the necessary device drivers to communicate with hardware devices.

2. File Management

The operating system manages files and folders.

It allows users to:

• Create files
• Delete files
• Copy files
• Move files
• Rename files
• Organise files

3. Memory Management

The operating system manages and allocates memory to different programs and processes according to their requirements.

4. Protection and Security

The operating system helps protect the computer system from:

• Unauthorised access
• Viruses
• Malware
• Other security threats

5. Process Management

The operating system manages the execution of different processes and ensures that tasks are performed properly.

6. Interrupt Handling

An interrupt is a signal that requires the attention of the CPU.

The operating system handles interrupts generated by:

• Hardware
• Software
• Input/output devices

7. Paging

Paging is a memory management technique in which memory is divided into fixed-size blocks called pages and frames.

It helps the operating system manage memory efficiently.

8. Virtual Memory

Virtual memory is a portion of storage space used temporarily as an extension of RAM.

It allows a computer to run programs even when the available physical RAM is insufficient.

RAM + Storage Space

        ↓

  Virtual Memory

9. Event Logging

Event logging records important system activities and events.

It is useful for:

• Tracking changes
• Troubleshooting
• Identifying errors
• Monitoring system activities

10. Process Scheduling

Process scheduling determines the order in which different processes are executed by the CPU.

It is especially important in multitasking operating systems.

Types of Scheduling

• Pre-emptive Scheduling: The operating system can interrupt a running process and assign the CPU to another process.
• Non-pre-emptive Scheduling: A process generally continues until it completes or voluntarily releases the CPU.

11. User Interface

A User Interface (UI) allows users to interact with the computer system.

Main Types

• Graphical User Interface (GUI): Uses windows, icons, menus and pointers.
• Command-Line Interface (CLI): Users interact with the system by typing commands.

12. Command Interpreter

A command interpreter interprets commands given by the user and instructs the operating system to perform the required operations.

Examples include:

• Command Prompt
• Shell

11. SPOOLING

Spooling stands for:

Simultaneous Peripheral Operations Online

Spooling is a process in which data is temporarily stored before being processed by a device or program.

Example: Printer Spooling

When several documents are sent to a printer:

Computer

↓

Printer Spooler

↓

Temporary Storage

↓

Printer

The documents are temporarily stored in a queue and printed one after another.

12. BUFFERING

Buffering is the process of temporarily storing data in a reserved area of memory called a buffer.

A buffer temporarily holds data while it is being transferred between:

• Two devices
• A device and an application
• A computer and a network

Example

Source → Buffer → Destination

Main Purpose

To temporarily hold data and ensure smooth data transfer.

13. TYPES OF OPERATING SYSTEM BASED ON NUMBER OF USERS

Single-User Operating System

A single-user operating system allows only one user to use the computer resources at a time.

Multi-User Operating System

A multi-user operating system allows multiple users to use computer resources.

14. WINDOWS OPERATING SYSTEM

Microsoft Windows is a family of proprietary graphical operating systems developed and marketed by Microsoft.

Microsoft introduced Windows on:

20 November 1985

It was initially introduced as a graphical operating system shell for MS-DOS.

Important Features

• Graphical User Interface
• Windows
• Icons
• Menus
• Taskbar
• Desktop
• File management
• Support for multiple applications

Taskbar: The taskbar provides access to programs and displays open applications.

It allows users to:

• Access programs
• View open applications
• Switch between applications

15. FILE

A file is a collection of related data or information stored under a particular name.

Examples of File Extensions

• .cpp → C++ source file
• .jpg → Image file
• .xml → XML file
• .java → Java source file

Important Point

Files have extensions to identify their type, whereas folders generally do not have file extensions.

16. FOLDER: A folder is a container used to store:

• Files
• Subfolders

Example of a File Path

F:\Study Material\Grade XI XII Slides

Important Features

• Folders must be given unique names within the same location.
• Folders can be shared over a network.

17. MY DOCUMENTS

My Documents is a default folder used in Windows for storing documents and personal files.

It may contain:

• Documents
• Personal files
• Other user data

Important Note

Files stored only on the system drive may be at risk of loss if the operating system is reinstalled or the drive is formatted. Therefore, important files should be backed up to another storage device or location.

18. FILE EXPLORER

File Explorer is a Windows utility used to browse and manage files and folders.

Common Operations

• Copy
• Paste
• Move
• Rename
• Delete
• Search
• Change folder layout
• View files and folders

It allows users to navigate to different locations where files and folders are stored.

19. RECYCLE BIN

The Recycle Bin is a temporary storage location for deleted files and folders in Windows.

Main Features

• Deleted files are temporarily stored in the Recycle Bin.
• Files can be restored to their original location.
• Files can be permanently deleted by emptying the Recycle Bin.

Restore Process

Deleted File

     ↓

Recycle Bin

     ↓

Restore

     ↓

Original Location

20. CONTROL PANEL

The Control Panel is a component of Microsoft Windows used to view and change system settings.

Common Uses

• Adding or removing hardware
• Adding or removing programs
• Managing user accounts
• Changing date and time
• Managing fonts
• Changing accessibility settings
• Accessing network settings

21. OPEN-SOURCE OPERATING SYSTEM

An open-source operating system is an operating system whose source code is publicly available.

This allows authorised users and developers to:

• View the source code
• Study the code
• Modify the code
• Improve the software
• Fix errors
• Add new features

Open Source vs Closed Source

Open Source	Closed Source
Source code is publicly available	Source code is generally not publicly available
Can be modified according to licence terms	Modification is generally restricted
Community development is possible	Development is controlled by the owner/developer

Copyleft

Copyleft is a licensing principle that allows users to use, modify and distribute software under specified conditions while preserving certain freedoms.

22. LINUX

Linux is a family of free and open-source Unix-like operating systems based on the Linux kernel.

Important Facts

• The Linux kernel was first released on 17 September 1991.
• It was developed by Linus Torvalds.
• Linux is released under the GNU General Public License (GPL).

Features of Linux

• Free and open source
• Flexible
• Portable
• Supports command-line interfaces
• Highly compatible
• Can be modified according to licence terms

MOBILE OPERATING SYSTEM

A mobile operating system is software that allows smartphones, tablets and other mobile devices to run applications and manage hardware resources.

Functions

• Runs mobile applications
• Manages wireless connectivity
• Manages cellular networks
• Controls device hardware
• Provides user interface
• Manages phone functions

Examples of Mobile Operating Systems

• Android
• iOS
• BlackBerry OS
• Bada
• Symbian OS
• HarmonyOS
• Palm OS
• webOS
• Windows Mobile

1. Which of the following is a collection of programs and associated data that provides instructions to a computer?

A. Hardware
B. Software
C. Firmware
D. CPU

Answer: B. Software

2. Which of the following is a physical component of a computer?

A. Software
B. Operating System
C. Hardware
D. Application

Answer: C. Hardware

3. Which of the following is system software?

A. MS Word
B. MS Excel
C. Operating System
D. PowerPoint

Answer: C. Operating System

4. The operating system acts as an interface between:

A. User and hardware
B. Software and printer only
C. Keyboard and mouse
D. Monitor and printer

Answer: A. User and hardware

5. Which of the following is NOT system software?

A. Operating System
B. Compiler
C. Assembler
D. MS Word

Answer: D. MS Word

6. Which software manages the hardware and software resources of a computer?

A. Application software
B. Operating system
C. Word processor
D. Spreadsheet

Answer: B. Operating system

7. Which of the following is an example of application software?

A. Windows
B. Linux
C. MS Word
D. Compiler

Answer: C. MS Word

8. Which of the following is a utility software?

A. Antivirus
B. MS PowerPoint
C. Web browser
D. Calculator

Answer: A. Antivirus

9. Utility software is mainly used to:

A. Create presentations
B. Maintain and optimise the computer system
C. Browse the Internet
D. Write programming code only

Answer: B. Maintain and optimise the computer system

10. Which of the following is used to detect and remove computer viruses?

A. Compiler
B. Antivirus software
C. Operating system
D. Text editor

Answer: B. Antivirus software

11. A program that translates assembly language into machine language is called:

A. Compiler
B. Interpreter
C. Assembler
D. Linker

Answer: C. Assembler

12. A compiler generally translates:

A. One statement at a time
B. The entire program at once
C. Only machine language
D. Only assembly language

Answer: B. The entire program at once

13. An interpreter translates a program:

A. Entirely before execution
B. One statement at a time
C. Only after compilation
D. From machine language to English

Answer: B. One statement at a time

14. Which of the following is a language translator?

A. Compiler
B. Monitor
C. Keyboard
D. Printer

Answer: A. Compiler

15. Translators are a type of:

A. System software
B. Application software
C. Hardware
D. Firmware only

Answer: A. System software

16. Which software is commonly known as the “soul” of a computer?

A. Hardware
B. Software
C. CPU
D. Memory

Answer: B. Software

17. Which of the following is an operating system?

A. Linux
B. MS Word
C. Google Chrome
D. Adobe Photoshop

Answer: A. Linux

18. Which of the following is an open-source operating system?

A. Linux
B. MS-DOS only
C. Windows only
D. iOS only

Answer: A. Linux

19. Linux was developed by:

A. Bill Gates
B. Steve Jobs
C. Linus Torvalds
D. Charles Babbage

Answer: C. Linus Torvalds

20. The Linux kernel was first released in:

A. 1985
B. 1991
C. 1995
D. 2001

Answer: B. 1991

21. Which of the following is a mobile operating system?

A. Android
B. MS Excel
C. Oracle
D. Photoshop

Answer: A. Android

22. Which of the following is a web-based application?

A. Google Docs
B. BIOS
C. Compiler
D. Device driver

Answer: A. Google Docs

23. Software designed to perform specific tasks for the end-user is called:

A. System software
B. Application software
C. Firmware
D. Utility hardware

Answer: B. Application software

24. Which software controls the overall operation of a computer?

A. Operating System
B. MS Word
C. Paint
D. Calculator

Answer: A. Operating System

25. Which of the following is NOT an operating system?

A. Windows
B. Linux
C. Android
D. MS Excel

Answer: D. MS Excel

26. Which of the following is used for file compression?

A. Utility software
B. Presentation software
C. Word processor
D. Operating system only

Answer: A. Utility software

27. Which software helps in managing files and folders?

A. File management utility
B. Compiler
C. Presentation software
D. Antivirus hardware

Answer: A. File management utility

28. Which of the following is an example of system software?

A. Device Driver
B. MS Word
C. MS Excel
D. PowerPoint

Answer: A. Device Driver

29. A device driver is a type of:

A. System software
B. Application software
C. Spreadsheet
D. Database

Answer: A. System software

30. Which of the following is used to create documents?

A. MS Word
B. Operating System
C. Compiler
D. Antivirus

Answer: A. MS Word

31. Which software is used to perform calculations and analyse data?

A. MS Excel
B. MS Word
C. Windows Explorer
D. Antivirus

Answer: A. MS Excel

32. Which software is used to create presentations?

A. MS PowerPoint
B. MS Excel
C. Linux
D. Compiler

Answer: A. MS PowerPoint

33. Which of the following is a function of an operating system?

A. Memory management
B. Process management
C. File management
D. All of the above

Answer: D. All of the above

34. Which of the following manages the execution of different processes?

A. Operating System
B. Keyboard
C. Monitor
D. Printer

Answer: A. Operating System

35. Which of the following is responsible for managing computer memory?

A. Operating System
B. Mouse
C. Printer
D. Scanner

Answer: A. Operating System

36. The process of temporarily storing data before it is used is called:

A. Buffering
B. Formatting
C. Booting
D. Debugging

Answer: A. Buffering

37. Spooling is particularly associated with:

A. Printing jobs
B. Keyboard typing only
C. Computer games only
D. Displaying images only

Answer: A. Printing jobs

38. Spooling stands for:

A. Simultaneous Peripheral Operations Online
B. System Peripheral Online Operation Language
C. Simultaneous Program Operation Online
D. System Processing Operations Online

Answer: A. Simultaneous Peripheral Operations Online

39. Which of the following is an example of closed-source operating system?

A. Linux
B. Windows
C. Ubuntu
D. Debian

Answer: B. Windows

40. In open-source software, the source code is:

A. Always hidden
B. Publicly available according to the licence terms
C. Stored only in hardware
D. Deleted after installation

Answer: B. Publicly available according to the licence terms

41. GUI stands for:

A. General User Interface
B. Graphical User Interface
C. Graphic Utility Internet
D. General Utility Interface

Answer: B. Graphical User Interface

42. CLI stands for:

A. Command-Line Interface
B. Computer Language Interface
C. Common Link Interface
D. Central Line Input

Answer: A. Command-Line Interface

43. Which of the following allows users to interact with a computer through icons and windows?

A. GUI
B. CLI
C. BIOS only
D. Compiler

Answer: A. GUI

44. Which of the following allows users to interact with a computer by typing commands?

A. GUI
B. CLI
C. Touchscreen only
D. Application software only

Answer: B. CLI

45. Which software provides a platform for running application software?

A. Operating System
B. Keyboard
C. Printer
D. Mouse

Answer: A. Operating System

46. Which of the following is an example of utility software?

A. Disk Cleanup
B. MS Word
C. PowerPoint
D. Calculator

Answer: A. Disk Cleanup

47. Which software is used to make backup copies of data?

A. Backup utility
B. Compiler
C. Word processor
D. Operating system kernel only

Answer: A. Backup utility

48. A program that converts high-level language into machine language is called:

A. Compiler
B. Assembler only
C. Device driver
D. File manager

Answer: A. Compiler

49. A program that translates and executes a high-level language statement by statement is:

A. Compiler
B. Interpreter
C. Assembler
D. Linker

Answer: B. Interpreter

50. Which of the following is the correct order of interaction?

A. User → Hardware → Software
B. User → Application Software → System Software → Hardware
C. Hardware → User → Software
D. Application Software → User → Hardware

Answer: B. User → Application Software → System Software → Hardware

51. Translators are a type of ___ softwares.

1. System
2. Application
3. utility
4. None of the above

Liaison Officer (LO) 2025

Answer: (A)

52. Which of the following does not translate the entire program at once?
 (A) Compiler
 (B) Interpreter
 (C) Assembler
 (D) Both (A) and (B)

Liaison Officer (LO) 2025

Answer: (B) Interpreter
Explanation: An interpreter reads, translates, and executes source code sequentially, statement by statement, whereas a compiler translates the entire source file into an executable file beforehand