Computer Hardware, Peripherals and Operating System Basics
This domain checks whether you can identify hardware components, classify peripherals correctly, and explain what an operating system actually does.
Hardware building blocks
- CPU - the processor: Arithmetic Logic Unit, Control Unit and registers. Speed is measured in GHz; modern CPUs have multiple cores.
- Primary memory - RAM is volatile (contents vanish on power off) and holds programs currently running; ROM is non-volatile and stores firmware such as the BIOS/UEFI used at start-up.
- Secondary storage - HDD, SSD, pen drive, memory card, optical disc. All non-volatile.
- Supporting parts - motherboard (connects everything), SMPS (power), ports: USB, HDMI, VGA, RJ-45 (network), audio jacks.
Peripherals
- Input only: keyboard, mouse, scanner, microphone, barcode reader, joystick.
- Output only: monitor, printer, plotter, speaker, projector.
- Both: touchscreen, modem, multifunction printer, pen drive (storage I/O).
- Printer types: impact (dot matrix - can print carbon copies), non-impact (inkjet, laser, thermal).
Operating system functions
Process management, memory management, file management, device management, security and the user interface. GUI uses windows/icons; CLI uses typed commands. Booting starts with POST (power-on self-test), then the bootloader loads the OS. Useful shortcuts: Ctrl+C copy, Ctrl+X cut, Ctrl+V paste, Ctrl+Z undo, Ctrl+S save, Alt+F4 close window.
Worked example
A shop needs multi-part carbon invoices, and a school needs 200 black-and-white pages a day as cheaply as possible. Answer: dot matrix for the shop (impact printing transfers to carbon copies) and laser for the school (fast, low cost per page, high-quality monochrome text).
Traps that cost marks
- Calling ROM volatile, or saying RAM stores files permanently.
- Labelling a touchscreen as input only, or a pen drive as input only.
- Mixing Ctrl+X (cut) with Ctrl+C (copy).
- Saying the CPU stores data permanently - it only holds registers and cache.