Know and understand advantages and disadvantages of the different types of computer including portability and expandability

1. Types and Components of Computer Systems

1.1 Types of Computer Systems

Supercomputers

Designed for extremely fast processing of large data sets, often used in scientific research, weather forecasting and cryptography.

• Advantages:

  • Very high processing speed (measured in petaflops).
  • Ability to run highly complex simulations.
  • Large memory capacity.

• Disadvantages:

  • Extremely high cost – both purchase and operating expenses.
  • Very large physical size; requires specialised facilities.
  • Low portability – cannot be moved easily.
  • Limited expandability for end‑users; upgrades are handled by manufacturers.

Mainframe Computers

Large, powerful systems used by organisations for bulk data processing, such as banking, airlines and government.

• Advantages:

  • High reliability and uptime.
  • Supports many simultaneous users.
  • Strong data security and backup options.
  • Scalable – can add processors, memory and storage.

• Disadvantages:

  • High acquisition and maintenance costs.
  • Requires dedicated space and cooling.
  • Not portable.

Servers

Computers that provide services (e.g., web, email, file storage) to other computers on a network.

• Advantages:

  • Can be configured for specific tasks.
  • Often designed for 24/7 operation.
  • Expandable through additional drives, RAM or network cards.

• Disadvantages:

  • Usually housed in racks – limited physical mobility.
  • Initial setup can be complex.
  • Power consumption can be significant.

Desktop Computers

Standard personal computers used at a fixed location, typically in homes or offices.

• Advantages:

  • Relatively low cost compared with larger systems.
  • Easy to upgrade – add RAM, storage, graphics cards, etc.
  • Wide range of software compatibility.

• Disadvantages:

  • Not portable – requires a permanent workspace.
  • Limited processing power compared with laptops designed for high‑performance tasks.

Laptop (Notebook) Computers

Portable computers that integrate screen, keyboard, battery and all components in a single unit.

• Advantages:

  • High portability – can be used anywhere with power or battery.
  • All‑in‑one design reduces cable clutter.
  • Often include wireless connectivity (Wi‑Fi, Bluetooth).

• Disadvantages:

  • Limited expandability – upgrades usually restricted to RAM and storage.
  • Smaller keyboards and screens may affect ergonomics.
  • Battery life varies; high‑performance models may drain quickly.

Tablet Computers

Touch‑screen devices primarily operated by finger or stylus input.

• Advantages:

  • Extreme portability – lightweight and thin.
  • Intuitive touch interface.
  • Long battery life for typical usage.

• Disadvantages:

  • Very limited expandability – usually cannot add RAM or internal storage.
  • Processing power lower than most laptops.
  • Limited peripheral support without adapters.

1.2 Components Common to All Computer Types

Regardless of size or form‑factor, every computer system contains the following core components:

• Central Processing Unit (CPU)
• Memory – Primary (RAM) and Secondary (Hard Disk / SSD)
• Motherboard (provides the bus architecture)
• Power Supply Unit (PSU)
• Input Devices (keyboard, mouse, touchpad, etc.)
• Output Devices (monitor, printer, speakers, etc.)
• Storage Interfaces (SATA, N \cdot Me, USB)
• Network Interfaces (Ethernet, Wi‑Fi, Bluetooth)

1.3 Comparison of Portability and Expandability

1.4 Summary

When selecting a computer system, learners should weigh the trade‑offs between:

1. Portability – how easily the device can be moved or used on the go.
2. Expandability – the ability to upgrade components to extend the system’s useful life.
3. Performance requirements – processing power, memory and storage needs.
4. Cost – initial purchase price versus long‑term upgrade costs.