Computer Science (9210) | Software classification

Hello Future Computer Scientists!

Welcome to the chapter on Software Classification! Don't worry if this sounds complicated—it just means we are learning how computers organise the programs they run.
Understanding how software is categorised is like knowing the different roles in a sports team: everyone has a specific job, and the computer system won't work without them.

By the end of these notes, you will be able to clearly identify the two main types of software and explain the difference between a custom-built program and a popular one you buy in a shop.

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The Big Divide: System Software vs. Application Software

All the programs, instructions, and data that a computer uses are called Software. We divide all software into two major families based on what they do:

1. System Software: The Manager

System Software manages the computer hardware and provides the platform (the foundation) for all other software to run. It's the essential background worker.
Think of System Software as the engine, chassis, and steering wheel of a car. You don't use these parts directly to drive to the park, but the car cannot move without them.

2. Application Software: The Tools

Application Software (often just called "Apps") allows the user to perform specific, useful tasks, like writing a letter, playing a game, or browsing the internet.
Think of Application Software as the car's GPS, the radio, or the cup holder—things that make your journey useful or enjoyable.

Key Takeaway: System software runs the computer; Application software helps the user do work.

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Section 1: Deep Dive into System Software

System software is usually split into two main categories required by the curriculum: the Operating System and Utility Programs.

A. The Operating System (OS)

The Operating System (OS) is the most important piece of system software. It acts as the central control program. When you switch your computer, phone, or tablet on, the OS is the first thing to load.

Key Jobs of the Operating System:

• Memory Management: Deciding where to store data and programs in the RAM (Random Access Memory).
• Resource Control: Managing all the hardware components (CPU, printer, monitor) so they don't crash into each other.
• User Interface (UI): Providing the screen you interact with (like Windows, macOS, or Android) so you don't have to type complicated codes.
• File Management: Organizing, saving, deleting, and naming files on the storage drives.

Did you know? Popular examples of Operating Systems include Windows 11, macOS, and Linux. For phones, the main ones are Android and iOS.

B. Utility Software

Utility Software consists of small programs that perform routine tasks to maintain and improve the computer system's performance and security.

Common Utility Programs:

1. Anti-Virus/Security Software: Scans for and removes malware (viruses, spyware) to keep the system safe.
2. Disk Defragmenter: Reorganizes files on the hard disk drive so that the computer can access them faster.

Simple Analogy: Imagine your notes for this class were ripped up and scattered randomly across the floor. Finding a specific note would take ages! Defragmentation puts all the pages of a file back together in one continuous spot on the drive, making access much quicker.

3. Compression Utilities: Reduce the size of files, making them easier to store and quicker to send over the internet (e.g., creating a .zip file).
4. Backup Utilities: Takes copies of files and saves them elsewhere, protecting you if the original data is lost or damaged.

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Section 2: Application Software – Categories by Purpose

Application software is categorized based on how widely it is used and who it was developed for. This is a crucial distinction to remember!

A. General Purpose Application Software

General Purpose Software (also known as Off-the-shelf software) is designed to perform common tasks that are useful to a large number of people.

• Accessibility: It is available for anyone to buy and use immediately.
• Flexibility: It is designed to be highly versatile and flexible (it can do many things).
• Cost: Usually less expensive than custom software because development costs are shared across millions of users.

Examples: Microsoft Word (used for writing letters, reports, poems, scripts—general tasks), standard web browsers like Chrome, or painting programs.

B. Special Purpose Application Software

Special Purpose Software is designed and built specifically to perform one unique, narrow task for one specific user or organisation.

• Uniqueness: It is often referred to as Bespoke (custom-made) software.
• Fit: It perfectly fits the exact needs of the user because they designed the requirements.
• Cost: Much more expensive to develop because all the development costs must be paid by the single client.

Example: The specific system used by a large bank to track internal employee payroll, a NASA system for controlling a specific space mission, or a custom inventory system designed only for one factory.

Common Mistake to Avoid: Don't confuse "specialist" applications (like advanced photo editing software) with "special purpose" (bespoke) software. If you can buy it in a shop, even if it is specialized, it is still General Purpose software.

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Section 3: Types of General Purpose Application Software

The curriculum requires you to know about several common types of application software and what they are used for:

1. Word Processing Software

Used for creating, editing, formatting, and printing text-based documents (letters, essays, reports).

• Examples: Microsoft Word, Google Docs.

2. Spreadsheet Software

Used for organizing, analysing, and manipulating data, usually in rows and columns. Excellent for performing complex calculations, modeling, and creating charts.

• Examples: Microsoft Excel, Google Sheets.

3. Database Management Software (DBMS)

Used for storing, organising, retrieving, and managing large amounts of structured data efficiently.

• Example: Microsoft Access, MySQL. You would use this to manage a customer list for a huge online shop.

4. Presentation Software

Used to create sequential slides that combine text, graphics, and video to present information to an audience.

• Examples: Microsoft PowerPoint, Google Slides.

5. Graphics and Multimedia Software

Used for creating or editing visual elements, audio, and video.

• Examples: Adobe Photoshop (for images), video editing tools like iMovie.