Software

System software runs the computer itself. It includes:

1. Operating System (OS) — the central program managing hardware, files, security, multitasking, user interface. Examples: Windows, macOS, Linux, Android, iOS.

2. Utility software — supports the OS and protects/maintains the system. Examples: antivirus, firewall, disk defragmenter, backup software, file compression (WinZip).

3. Device drivers — translate generic OS commands into hardware-specific instructions for printers, graphics cards, scanners, etc.

Application software performs tasks for the user:

1. Productivity apps — word processors (Word, Google Docs), spreadsheets (Excel, Sheets), databases (Access, MySQL), presentations (PowerPoint, Slides), email clients (Outlook, Gmail).

2. Creative apps — image editors (Photoshop, GIMP), video editors (Premiere, DaVinci Resolve), audio editors (Audacity), CAD (AutoCAD).

3. Communication — browsers (Chrome, Firefox), messaging (WhatsApp, Teams), social media apps.

4. Specialised — accounting (Xero), project management (Jira), industry-specific tools.

5. Entertainment — games, streaming services, media players.

1. Memory management — allocates RAM between running programs; ensures memory protection (one program can't read another's memory without permission); manages virtual memory (using disk as overflow RAM).

2. File management — organises files into folders; tracks physical location on disk; provides services for creating, copying, moving, deleting files; manages file permissions.

3. Multitasking (process management) — allows multiple programs to run apparently simultaneously by rapidly switching CPU attention between them. Modern OSes use multi-core CPUs to truly run multiple processes in parallel.

4. Security and authentication — login/passwords, user accounts and permissions, encryption, anti-malware integration, locking screens.

5. User interface (UI) — graphical (Windows desktop, macOS Finder, Android home screen) or command-line (Linux terminal). Manages mouse, keyboard, touch, voice input.

6. Hardware management — communicates with hardware via drivers; manages peripherals (printers, scanners, cameras); monitors temperature and power.

Mnemonic: M-F-M-S-U-H — 'Memory, File, Multitasking, Security, UI, Hardware'.

Aspect	Open-Source	Proprietary
Source code	Public, modifiable	Private, locked
Cost	Usually free	Usually paid
Support	Community (forums, docs)	Vendor (phone, chat)
Reliability	Varies by project	Generally consistent for major vendors
Updates	Community-driven	Vendor schedule
Lock-in risk	Low (you can fork)	High (depends on vendor)
Customisation	Full	Limited

Examples — Open-source:

• Linux (Ubuntu, Fedora) — OS.
• LibreOffice — productivity suite.
• GIMP — image editor.
• Firefox — browser.
• Audacity — audio editor.

Examples — Proprietary:

• Microsoft Windows, macOS — OS.
• Microsoft Office, Adobe Creative Cloud — productivity/creative.
• Photoshop, AutoCAD — specialised.

Hybrid: some companies offer dual licences — free for personal use, paid for commercial.

Bespoke (custom) software is developed for one specific organisation's requirements:

• Advantages: Exact fit to business needs; competitive advantage; specific workflows.
• Disadvantages: Expensive (£10k–£millions); slow to develop (months/years); ongoing maintenance burden; risk of developer leaving.

Off-the-shelf software is mass-produced and sold to anyone:

• Advantages: Cheap (£0–£500/user); immediate availability; vendor support; large user base for help; regular updates.
• Disadvantages: Generic features may not fit specific needs; vendor controls roadmap; possible feature bloat.

When to choose bespoke:

• Highly specialised industry (e.g., custom CAD for niche manufacturing).
• Competitive differentiation needed.
• Large enterprise with deep pockets and unique requirements.

When to choose off-the-shelf:

• Common needs (office productivity, accounting, email).
• Small/medium business with tight budget.
• Standard industry workflows.

Customisation of off-the-shelf is a middle ground — buy off-the-shelf and configure it (e.g., Salesforce, SAP).

Cloud software (SaaS — Software as a Service):

• Hosted on provider's servers.
• Accessed via web browser or thin client.
• Subscription pricing (monthly/yearly).
• Automatic updates.
• Multi-device access — work from any browser.
• Data stored in the cloud.

Examples: Google Workspace, Microsoft 365 Online, Salesforce, Xero.

Installed software:

• Downloaded and installed locally on each device.
• One-off purchase OR perpetual licence.
• User manages updates.
• Works offline.
• Data typically stored locally (with backup).

Examples: Microsoft Office desktop, Adobe Photoshop installed.

Trade-offs:

• Cloud: lower upfront cost, always up-to-date, accessible anywhere — but requires internet, ongoing subscription cost, vendor data privacy concerns.
• Installed: works offline, one-off cost may be cheaper long-term, full local data control — but device-tied, manual updates, no real-time collaboration.

Many modern products offer hybrid — installed app with cloud sync (e.g., Adobe Creative Cloud).

Single-user licence — one user, often tied to a device.

Multi-user (concurrent) licence — N users can use simultaneously (e.g., 10 floating licences shared across 30 employees).

Site licence — entire organisation/location can use (typical for schools, large corporations).

Subscription — pay monthly/yearly for ongoing access. Includes updates.

Perpetual — pay once, use forever (may need to pay for updates).

Freeware — free to use, but creator retains rights.

Shareware — free trial, must pay after a period or for full features.

Open source (FOSS) — free to use, modify, redistribute (under specific licences like GPL, MIT, Apache).

Examination tip: ICT questions often test 'which licence best suits a school of 500 students?' Answer: site licence — economical and simple to administer.