Know and understand hardware components including graphics card, sound card, Network Interface Card (NIC), camera, internal/external storage devices, input and output devices

Topic: Hardware Components, Operating Systems, Networks and Emerging Technologies

Learning Objective

Know and understand the hardware components of a computer system (internal and external), the different types of computers, operating‑system interfaces, basic networking devices and concepts, emerging technologies, and the effects of using IT.

1. Types of Computer Systems

• Desktop computers – stationary, separate monitor, keyboard and mouse.
• Laptop/Notebook computers – portable, integrated display, keyboard and battery.
• Tablet computers – touch‑screen, often without a physical keyboard.
• Smartphones – handheld devices for communication, apps and internet access.
• Phablets – larger smartphones (≈6–7 in) that combine phone functions with tablet‑style media consumption.
• Servers – provide services (file sharing, web hosting, email) to other computers on a network.
• Mainframes – large, high‑capacity systems for bulk data processing in organisations.
• Supercomputers – extremely high‑performance machines for scientific and engineering calculations.

2. Core Internal Components

2.1 Central Processing Unit (CPU)

• “Brain” of the computer – fetches, decodes and executes instructions.
• Mounted in a socket on the motherboard; usually has an integrated heat‑sink and fan.
• Examples: Intel Core i5/i7, AMD Ryzen 5/7.

2.2 Motherboard

• Main printed‑circuit board that interconnects all components.
• Provides slots for expansion cards (PCI‑Express), connectors for storage (SATA, M.2) and ports for I/O devices.
• Contains the chipset, BIOS/UEFI firmware and power‑distribution circuitry.

2.3 Internal Memory

• RAM (Random‑Access Memory) – volatile memory used for temporary data while programmes run (typical capacities 4 GB–32 GB).
• ROM (Read‑Only Memory) – non‑volatile memory that stores firmware such as the BIOS/UEFI; it is not user‑upgradeable.
• Both are mounted on the motherboard in DIMM slots.

3. Expansion & Interface Cards

• Graphics Card (Video Card)

  • Renders images, video and 3‑D graphics; contains a GPU and dedicated video RAM (VRAM).
  • Plugs into a PCI‑Express x16 slot.
  • Outputs to a monitor via HDMI, DisplayPort, DVI or VGA.

• Sound Card

  • Processes audio input and output; converts digital signals to analog and vice‑versa.
  • Often integrated on the motherboard; dedicated cards improve audio quality.
  • Provides ports for speakers, headphones and microphones.

• Network Interface Card (NIC)

  • Enables wired Ethernet or wireless Wi‑Fi connectivity.
  • Contains a unique MAC address for network identification.
  • Can be built‑in or added via a PCI‑e slot.

• Camera (Webcam)

  • Captures still images and video for communication and recording.
  • Usually connects via USB; many laptops have an integrated webcam.

4. Storage Devices & Media

4.1 Internal (Primary) Storage

• Hard Disk Drive (HDD) – magnetic platters; large capacity, slower access.
• Solid‑State Drive (SSD) – flash memory; fast access, resistant to shock.
• Optical Drive – uses lasers to read/write optical media (CD, DVD, Blu‑ray).
• Magnetic Tape – sequential magnetic storage used for large‑scale backups.

4.2 External (Secondary) Storage

• USB flash drives, external HDD/SSD, memory cards (SD, microSD), external optical drives.
• Connected via USB, Thunderbolt, eSATA or wireless protocols.

5. Input Devices

• Keyboard – primary text entry device.
• Mouse – pointer control; wired, wireless or Bluetooth.
• Touchpad – finger‑sensing surface on laptops.
• Touchscreen – direct finger or stylus interaction (tablet, smartphone).
• Scanner – converts physical documents or images into digital form.
• Microphone – captures audio for recording or communication.
• Joystick / Gamepad – specialised input for gaming and simulations.
• Light‑pen – pen‑like device that detects light on a CRT or LCD screen.

6. Output Devices

• Monitor (Display) – visual output; LCD, LED, OLED technologies.
• Printer – hard‑copy production; inkjet, laser, dot‑matrix, multifunction.
• Speakers – audio output for music, alerts and multimedia.
• Projector – enlarges visual output onto a screen or wall.
• Actuator – device that converts electrical signals into mechanical movement (used in robotics, printers).
• 3‑D Printer – builds three‑dimensional objects layer by layer from plastic, metal or resin.

7. Operating Systems (OS) – Interface Types

• Command‑Line Interface (CLI) – users type textual commands (e.g., MS‑DOS, Linux terminal).
• Graphical User Interface (GUI) – visual icons, windows and menus.
• Dialogue‑based Interface – wizard‑style dialogs that guide the user step‑by‑step (e.g., installation wizards).
• Gesture‑based Interface – touch gestures such as pinch‑to‑zoom, swipe, tap‑and‑hold on tablets and smartphones.

8. Emerging Technologies (Brief Overview)

• Artificial Intelligence (AI) – voice assistants (Siri, Google Assistant), predictive text, image recognition.
• Extended Reality (XR) – virtual reality (VR) headsets, augmented reality (AR) overlays on mobile devices, mixed reality (MR) applications.

9. Networks & Their Effects

9.1 Network Devices

• Network Interface Card (NIC) – provides Ethernet/Wi‑Fi connectivity; contains a MAC address.
• Router – forwards data between different networks, stores routing tables, often includes NAT and DHCP functions.
• Switch – connects multiple devices on the same LAN, forwards frames based on MAC addresses.
• Hub – simple device that repeats incoming signals to all ports (no addressing).
• Bridge – links two LAN segments and filters traffic using MAC addresses.

9.2 Network Types & Terminology

• LAN (Local Area Network) – covers a single building or campus.
• WLAN (Wireless LAN) – LAN that uses Wi‑Fi.
• WAN (Wide Area Network) – spans cities, countries or continents (e.g., the Internet).
• Intranet – private network accessible only within an organisation.
• Extranet – controlled access to an organisation’s intranet for external partners.
• Internet – global network of networks.

9.3 Wireless & Short‑Range Technologies

• Wi‑Fi (IEEE 802.11) – wireless LAN standard.
• Bluetooth – short‑range (≤10 m) communication for peripherals and IoT devices.

9.4 Security Basics & E‑Conferencing

• Strong passwords – minimum length, mix of letters, numbers and symbols; regular change.
• Anti‑malware software – scans for viruses, spyware and ransomware.
• E‑conferencing tools – video/audio/web conferencing (e.g., Zoom, Teams, Google Meet) – rely on network bandwidth and security (encryption, passwords).
• Awareness of phishing, social engineering and safe‑browsing practices.

10. Effects of Using IT

• Micro‑processor‑controlled devices – smart home appliances, autonomous vehicles, wearable fitness trackers.
• Health considerations – eye strain, musculoskeletal problems from prolonged use, importance of breaks and ergonomic setups.
• Environmental impact – e‑waste, energy consumption, recycling of electronic components.

11. Summary Table of Key Components

12. Quick Revision Checklist

1. Identify the purpose of each expansion card (graphics, sound, NIC, webcam).
2. Explain the difference between internal memory (RAM/ROM) and backing storage (HDD/SSD, external media, magnetic tape).
3. List at least three input devices and three output devices, including light‑pen and 3‑D printer.
4. Describe how a NIC enables network communication and why the MAC address is unique.
5. State two advantages of an SSD over an HDD.
6. Differentiate between CLI, GUI, dialogue‑based and gesture‑based operating‑system interfaces.
7. Define LAN, WLAN, WAN, intranet, extranet and internet.
8. Give one example each of a router, switch, hub and bridge and their basic function.
9. Outline two basic security measures for safe network use (e.g., strong passwords, anti‑malware).
10. Identify two health or environmental effects of prolonged IT use.

13. Suggested Classroom Activities

• Component identification: Disassemble a desktop (or use a mock‑up) and have students label the CPU, RAM, motherboard, expansion slots, storage devices and NIC.
• Matching game: Cards with component names versus cards with functions; students work in teams to pair them correctly.
• Research mini‑presentations: Each group investigates a specific topic (e.g., GPU architecture, SSD NAND types, Wi‑Fi 6 standards, AI assistants) and delivers a 3‑minute report.
• Hands‑on demo: Connect a USB flash drive, an external HDD and a webcam to a laptop; observe device recognition, driver installation and file transfer.
• OS exploration: Boot a computer into safe mode/command line and compare it with the normal graphical desktop.
• Network simulation: Use a simple network‑simulation tool (e.g., Cisco Packet Tracer) to set up a LAN with a router, switch and two PCs; demonstrate IP addressing and data flow.
• Ergonomics workshop: Assess workstation posture, adjust chair/monitor height, and discuss regular break routines.

14. Summary

Understanding the full range of hardware components—from the CPU and motherboard to expansion cards, storage media and I/O devices—together with operating‑system interfaces, basic networking concepts and emerging technologies, equips IGCSE ICT learners to troubleshoot, upgrade, and make informed decisions about technology use. Awareness of security practices and the health and environmental effects of IT completes a well‑rounded foundation for further study and real‑world application.