Hardware and Operating System Basics
This domain tests how computer hardware components work together and what an operating system does for the user and the machine.
Hardware essentials
- The CPU contains the ALU (arithmetic and logic), control unit, and registers. It executes instructions.
- Primary memory: RAM (volatile working memory), ROM (firmware), cache (fast, small). Secondary storage: HDD, SSD, pen drive, optical disc.
- The motherboard connects components through buses and provides ports such as USB, HDMI, VGA, and Ethernet.
Operating system functions
An OS manages processes, memory, files, devices, and users, and provides a user interface. GUI uses windows, icons, and menus; CLI uses typed commands. A file has a name and an extension that indicates its type, such as .docx or .xlsx.
Worked example
A user presses Print and the document waits in a queue while another job finishes. The component responsible is the operating system's device management and print spooler, not the word processor. The application creates the print job; the OS schedules it and manages the printer device. This distinction is what the question is testing.
Traps that cost marks
- Saying RAM is permanent storage; RAM is volatile.
- Confusing memory with storage capacity.
- Treating file extensions as optional when identifying file type.
- Claiming the control unit performs calculations; the ALU does arithmetic and logic.