Hardware, Software and Operating System Basics
What this domain tests
Questions here separate the physical machine from the instructions that drive it. You should know the main hardware units, the difference between system and application software, and the basic jobs an operating system performs.
Core rules
- CPU components: ALU performs arithmetic and logic; control unit fetches, decodes and executes instructions; registers hold very fast temporary data.
- Memory hierarchy: registers → cache → RAM → secondary storage. RAM is volatile; ROM is non-volatile and holds firmware such as BIOS/UEFI.
- Input devices send data in; output devices present results; secondary storage keeps data permanently.
- System software includes the operating system, device drivers and utilities. Application software performs user tasks such as word processing.
- An OS manages processes, memory, files and devices, and provides a user interface.
- Booting loads the OS; open-source software allows access to source code, proprietary software does not.
Worked example
Classify: Ubuntu, MS Word, a printer driver, an antivirus utility. Ubuntu is an operating system, so system software. MS Word is an application for document creation. A printer driver is system software because it lets the OS communicate with hardware. An antivirus utility is system software/utility because it maintains the system rather than producing user documents.
Traps
- RAM is working memory, not permanent storage; saving to RAM does not survive power-off.
- Firmware is software stored in ROM, not hardware.
- A GUI is an interface, not the whole operating system.
- Do not call every program “application software”; drivers and utilities are system software.