Computer Software

A brand-new laptop with no software is a box of metal, plastic and glass: it cannot even show a picture on its screen. Everything a computer does — starting up, showing a desktop, printing an essay, playing a song, paying a bill — is done by software. This lesson explains what software is and why it matters, the two big families of software (system and application), the licences that decide whether you may copy or change a program, and how to install, update and remove software safely.

5.1 Software: meaning and importance; how hardware and software work together

Software cannot be touched, but without it hardware cannot do anything.

Importance of software

• It makes hardware work: it switches devices on, reads the keyboard, shows pictures on the screen and sends pages to the printer.
• It lets people use the computer without knowing electronics, through icons, menus and touch.
• It makes one computer versatile: install a new program and the same machine becomes a typewriter, a cinema, a calculator or a classroom.
• It solves real problems in every field — results in schools, accounts in banks, records in hospitals, tickets in airlines.
• Updates to software fix mistakes, close security holes and add features without changing the hardware.

How hardware and software work together

Software is arranged in layers. You talk to an application; the application asks the operating system; the operating system uses a device driver; the driver controls the hardware.

Even switching on a computer uses the layers. A small program stored permanently in a chip on the motherboard — the firmware, called BIOS or UEFI — checks the hardware and loads the operating system from the disk into RAM. The operating system then loads the device drivers, shows the desktop and waits for you to open an application. This start-up process is called booting.

5.2 System software: operating system, device drivers, utility programs and language processors

1. Operating system

The operating system (OS) is the most important system software. It controls all the hardware, manages memory and files, runs other programs and gives the user a way to work with the computer. Examples: Windows 11, macOS, Linux (Ubuntu, Fedora), Android and iOS. Lesson 6 is about operating systems.

2. Device drivers

Every device has its own driver, written by its maker. Most common drivers come with the operating system, so a mouse or pen drive works as soon as it is plugged in (plug and play). For other devices — many printers, scanners and graphics cards — the driver must be installed from the maker's website or from the disc in the box, or the device will not work. In Windows, Device Manager (right-click the Start button → Device Manager) lists every device; a yellow warning sign beside a device means its driver is missing or not working.

3. Utility programs

Utility	What it does	Examples
Antivirus	finds and removes viruses and other malware	Microsoft Defender (Windows Security), Avast, Kaspersky
Backup	copies files so they can be restored after a loss	File History, OneDrive or Google Drive backup
File compression	makes files smaller, packs many into one ZIP file	7-Zip, WinRAR, Windows' built-in ZIP
Disk cleanup	deletes temporary and unwanted files to free space	Disk Cleanup, Storage Sense, BleachBit
Disk defragmenter	rearranges the pieces of files on a hard disk so they are read faster	Defragment and Optimize Drives
System monitor	shows running programs and how busy the CPU and memory are	Task Manager (Ctrl + Shift + Esc)

4. Language processors

Computers understand only machine language — instructions written in 0s and 1s. People write programs in easier languages such as Python, C or QBASIC. A language processor (translator) converts them.

• An assembler translates a program written in assembly language (short codes such as ADD and MOV) into machine language.
• A compiler translates the whole high-level program into machine language at once, producing a separate program file that can then be run again and again without translating. C and C++ use compilers.
• An interpreter translates and runs a high-level program one line at a time, and stops at the first line with an error. Python and QBASIC use interpreters.

Compiler	Interpreter
translates the whole program at once	translates and runs one line at a time
lists all the errors after translating	stops at the first error it meets
makes a separate machine-language file (e.g. an .exe)	makes no separate file; needs the source every time
the finished program runs fast	runs more slowly, as each line is translated each time
e.g. C, C++ compilers	e.g. Python, QBASIC interpreters

5.3 Application software: packaged and tailor-made software

Packaged software

Packaged software (general-purpose or ready-made software) is made by a software company for a very large number of users with similar needs and is sold or given away as a finished product. You can buy, download and use it straight away.

Kind of work	Examples of packaged software
Word processing	Microsoft Word, LibreOffice Writer, Google Docs
Spreadsheet	Microsoft Excel, LibreOffice Calc, Google Sheets
Presentation	Microsoft PowerPoint, LibreOffice Impress, Canva
Web browsing	Google Chrome, Mozilla Firefox, Microsoft Edge
Graphics and photo editing	Adobe Photoshop, GIMP, Canva
Audio and video	VLC media player, Audacity
Communication	Zoom, Viber, WhatsApp, Microsoft Teams
Accounting	Tally Prime

A set of related packaged programs sold together is a suite, for example Microsoft 365 (Word, Excel, PowerPoint, Outlook) and LibreOffice (Writer, Calc, Impress, Draw, Base).

Tailor-made software

Tailor-made software (customized or bespoke software) is developed for one particular organization or person, to fit their own way of working exactly, just as a tailor stitches a suit to one person's measurements.

Examples: the school management system of a particular school (students' records, fees, attendance and report cards in its own format); a hospital management system; the core banking system of a bank; the result processing software of an examination board; the billing system of a water or electricity office; and government apps such as the Nagarik App, built for the Government of Nepal.

Packaged software	Tailor-made software
made for many users with common needs	made for one organization's own needs
ready to use immediately	takes time to design, write and test
cheaper, because its cost is shared by many buyers	costly, because one client pays for it all
may have features you never use and lack some you need	has exactly the features the client asked for
updated by the maker for everyone	changed only when the client asks
e.g. MS Word, Excel, VLC	e.g. a school's result system, a bank's core system

Today much application software comes as mobile apps (installed on Android or iOS phones) or web applications, which run inside a browser without installing anything — for example Gmail and Google Docs.

System software	Application software
controls and manages the hardware	helps the user do a particular task
starts when the computer starts and runs until shut-down	runs only when the user opens it
needed for the computer to work at all	the computer works without it, but does nothing useful for you
installed with the computer (mostly with the operating system)	installed by the user as needed
the user rarely works with it directly	the user works with it directly
e.g. Windows, Android, drivers, antivirus, compiler	e.g. Word, Chrome, games, a school's result software

5.4 Software licences: proprietary, freeware, shareware and open-source software

When you install software you are not buying the program itself, only the right to use it under certain conditions. Those conditions are its licence.

Proprietary software (commercial or closed-source software) is owned by a company that keeps its source code secret. You must buy a licence to use it, and you may not copy, share or change it. Examples: Microsoft Windows, Microsoft 365 (Office), Adobe Photoshop, macOS, Tally Prime, AutoCAD.

Freeware is software that can be used free of cost for as long as you like, but the owner keeps the copyright and the source code is closed: you may not change it or sell it. Examples: Google Chrome, Zoom (basic plan), Adobe Acrobat Reader, WhatsApp, Viber.

Shareware is software you may try free for a limited time or with some features locked, and then must pay for to keep using fully ("try before you buy"). Examples: WinRAR (40-day trial), Internet Download Manager (30-day trial), WinZip.

Open-source software is software whose source code is open for anyone to read, use, change and share, under a licence such as the GNU GPL. It is usually free of cost and is improved by programmers all over the world. Examples: Linux (Ubuntu, Fedora), LibreOffice, Mozilla Firefox, VLC media player, GIMP, Audacity, Python, Moodle and the core of Android.

Licence type	Cost	Can use freely?	Can see source code?	Can change and share?	Examples
Proprietary	must buy	only with a paid licence	no	no	Windows, MS Office, Photoshop
Shareware	free trial, then pay	only during the trial	no	no	WinRAR, IDM, WinZip
Freeware	free	yes	no	no	Chrome, Zoom, Acrobat Reader
Open source	usually free	yes	yes	yes, under its licence	Linux, LibreOffice, Firefox, VLC

5.5 Installing, updating and removing software safely

Installing means copying a program onto the computer and setting it up so that it runs. Updating replaces it with a newer version. Uninstalling removes it completely.

Before you install

1. Check the system requirements — the operating system version, RAM and free disk space the program needs — against your computer.
2. Download only from the official source: the Microsoft Store, Google Play, Apple's App Store, a Linux software centre, or the maker's own website.
3. Never install cracked or pirated software or apps from unknown links; they are illegal and are the commonest way viruses get in.
4. You may need an administrator password to install programs.

1Operating system and its version2Processor (CPU)3Memory: the size of the RAM4Disk capacity: compare the free space with what the program needs

Installing a program on Windows 11

1. Open the Microsoft Store, search for the program and click Get (or Install). The Store installs it for you.
2. Or download the installer (a .exe or .msi file) from the maker's official website and double-click it.
3. Windows asks, "Do you want to allow this app to make changes to your device?" Check that the publisher's name is the real maker, then click Yes.
4. Read the licence agreement and accept it.
5. Choose Custom setup where offered and untick extra programs, toolbars or offers you did not ask for.
6. Click Install, wait, then Finish. The program appears in the Start menu.

On an Android phone, open Google Play, search, check the developer's name, ratings and the permissions the app asks for, and tap Install. Do not install APK files from unknown sources.

1Search: type a program's name to find it2Explore: browse new software and install it3Installed: every installed program, each with a button to remove it4Updates: download new versions of all programs at once5Categories of software: Create, Work, Play, Socialise, Learn, Develop

Updating

Updates fix bugs, close security holes that attackers use, and add new features. Keep automatic updates switched on.

• Windows: Settings → Windows Update → Check for updates.
• Microsoft Store apps: open the Store → Downloads at the bottom left (called Library in older versions) → Check for updates.
• Android apps: Google Play → tap your profile picture → Manage apps & device → Update all.
• Update device drivers from Windows Update or the maker's website.

Software that no longer receives security updates is unsafe to use online. Microsoft stopped ordinary support for Windows 10 on 14 October 2025, so computers that still run it should be moved to a supported system.

Removing (uninstalling)

• Windows 11: Settings → Apps → Installed apps → click the three dots (⋯) beside the program → Uninstall → confirm. (Control Panel → Programs and Features also works.)
• Android: touch and hold the app's icon → App info → Uninstall.
• Linux: in the software centre, open Installed and click Uninstall.

Chapter summary

• Software is a set of programs that tells the hardware what to do; it makes the computer usable, versatile and useful. It works in layers: user → application → operating system → device driver → hardware.
• System software manages the computer: the operating system, device drivers (one for each device), utility programs (antivirus, backup, compression, disk cleanup) and language processors.
• Assembler: assembly → machine code. Compiler: whole program at once, separate file, fast. Interpreter: line by line, stops at the first error.
• Application software does the user's tasks: packaged (ready-made for many users — Word, Chrome, VLC) or tailor-made (built for one organization — a school's result system).
• Licences: proprietary (buy; code secret), freeware (free; code secret), shareware (free trial, then pay), open source (free; code open to change and share). Piracy is illegal.
• Install only from official sources, check requirements, keep software updated, and remove programs with Uninstall, not by deleting icons.

Practice questions

Group A — Objective (1 mark each)

1. A set of programs that tells the hardware what to do is called [1]ahardwarebsoftwarecfirmware onlyddata
2. Which of these is system software? [1]aMicrosoft WordbWindows 11cVLC media playerda game
3. A program that lets the operating system control a printer is a [1]acompilerbdevice drivercutilitydspreadsheet
4. Which is a utility program? [1]aantivirusbPowerPointcChromedTally
5. A translator that runs a program one line at a time is [1]aa compilerban assemblercan interpreterda driver
6. Assembly language is translated into machine language by [1]aan assemblerban interpreterca browserdan operating system
7. Software made for one particular organization is [1]apackaged softwarebtailor-made softwarecfreewaredshareware
8. Software that can be used free for 30 days and must then be bought is [1]afreewarebopen sourcecsharewaredproprietary only
9. Which of these is open-source software? [1]aMicrosoft OfficebLibreOfficecAdobe PhotoshopdWinRAR
10. Google Chrome is an example of [1]afreewarebsharewarecopen-source softwaredtailor-made software
11. The safe way to remove a program from Windows 11 is [1]adelete its desktop iconbdelete its foldercSettings → Apps → Installed apps → Uninstalldempty the Recycle Bin
12. Using a cracked copy of a paid program is called [1]aupdatingbsoftware piracycopen sourcingdcompiling

Answers to Group A

1. (b) — software tells the hardware what to do.

2. (b) — the operating system is system software.

3. (b) — each device needs its own driver.

4. (a) — antivirus protects the computer; the others are applications.

5. (c) — an interpreter works line by line.

6. (a) — the assembler handles assembly language.

7. (b) — tailor-made (customized) software.

8. (c) — shareware: try, then buy.

9. (b) — its source code is open.

10. (a) — free to use but its code is closed.

11. (c) — always use the Uninstall command.

12. (b) — piracy is illegal under the Copyright Act.

Group B — Short answer (2 marks each)

1. What is software? Write two reasons why it is important. [2]
2. Differentiate between system software and application software. [2]
3. What is a device driver? Why is it needed? [2]
4. What is a utility program? Name any three. [2]
5. Differentiate between a compiler and an interpreter in two points. [2]
6. Differentiate between packaged and tailor-made software, with one example of each. [2]
7. What is open-source software? Give two examples. [2]
8. Differentiate between freeware and shareware. [2]
9. Write the steps to uninstall a program in Windows 11. [2]
10. Why should software be updated regularly? Give two reasons. [2]

Answers to Group B

1. Software is a set of programs that tells the computer's hardware what to do. It is important because hardware cannot work without it, and because it makes the computer versatile — the same machine does many tasks by running different software. (Also: lets people use the computer easily; solves problems in every field.)

2. System software controls and manages the hardware and runs whenever the computer is on (e.g. Windows, drivers). Application software helps the user do a particular task and runs only when opened (e.g. MS Word, Chrome).

3. A device driver is a small program that lets the operating system communicate with and control one particular device, such as a printer or graphics card. Without the right driver, the operating system cannot use the device, so it will not work.

4. A utility program is system software that maintains, protects or improves the computer and its data. Examples: antivirus (Microsoft Defender), file compression (7-Zip), disk cleanup, backup, Task Manager.

5. A compiler translates the whole program at once and makes a separate machine-code file; an interpreter translates and runs one line at a time and makes no file. A compiler lists all errors after translating; an interpreter stops at the first error. (E.g. C uses a compiler; Python an interpreter.)

6. Packaged software is ready-made for many users with common needs and is cheaper, e.g. Microsoft Excel. Tailor-made software is written for one organization's own needs and is costlier, e.g. a school's own result-processing system.

7. Open-source software is software whose source code is open for anyone to use, read, change and share under its licence; it is usually free. Examples: Linux, LibreOffice, Firefox, VLC, Python (any two).

8. Freeware can be used free of cost with no time limit (but its code is closed), e.g. Google Chrome. Shareware can be used free only for a trial period or with limited features and must then be bought, e.g. WinRAR.

9. Open Settings → Apps → Installed apps; find the program, click the three dots (⋯) beside it and choose Uninstall; confirm by clicking Uninstall again and follow any instructions.

10. Updates fix bugs (mistakes) in programs and close security holes that viruses and hackers use; they also add new features and keep the software working with new hardware and files.

Group C — Long answer (4 marks each)

1. What is system software? Explain its four types with examples. [1+3]
2. Explain how hardware and software work together when you print a document, with a diagram. [4]
3. Explain proprietary, freeware, shareware and open-source software with an example of each. [4]
4. Describe how to install software safely on a Windows computer, and give two precautions. [4]
5. A hospital wants(a) to type letters,(b) to keep its own patient, ward and billing records in its own format,(c) to protect its computers from viruses and(d) to run its new X-ray printer. Name the type of software needed for each, with an example. [4]

Answers to Group C

1. System software is the group of programs that controls and manages the hardware and provides a base for application software (1 mark). Operating system: manages hardware, memory, files and programs and gives the user an interface — Windows 11, Linux, Android. Device drivers: let the OS control one device — a printer or graphics card driver. Utility programs: maintain and protect the computer — antivirus, backup, disk cleanup, 7-Zip. Language processors: translate programs into machine language — assembler, compiler (C), interpreter (Python).

2. Draw the layer diagram (Figure 1): user → application software → operating system → device driver → hardware. The user clicks Print in the word processor; the application prepares the pages and sends a print request to the operating system; the OS queues the job and passes it to the printer's driver; the driver converts it into commands that this model of printer understands; the printer hardware prints the page. Each layer communicates only with the next.

3. Proprietary: owned by a company, code secret, must buy a licence, cannot copy or change — Microsoft Windows, MS Office. Freeware: free of cost to use, but code closed and cannot be changed — Google Chrome, Zoom. Shareware: free for a trial period or with limited features, then must be bought — WinRAR, Internet Download Manager. Open source: source code open; anyone may use, change and share it, usually free — Linux, LibreOffice, Firefox.

4. Steps: check the system requirements; download from the Microsoft Store or the maker's official website; run the installer; at the "allow this app to make changes" prompt check the publisher and click Yes; accept the licence; choose Custom setup and untick unwanted extra programs; click Install, then Finish. Precautions (any two): never install cracked or pirated software; download only from official sources; keep the antivirus on; check free disk space first; be careful of extra toolbars and offers.

5. (a) Packaged application software, a word processor — MS Word or LibreOffice Writer. (b) Tailor-made application software — a hospital management system written for that hospital. (c) Utility software, an antivirus — Microsoft Defender or Kaspersky. (d) System software, a device driver — the X-ray printer's driver from its maker.