Hardware, Software and Operating Systems
Hardware, Software and Operating Systems
This domain covers the physical computer, the programs that run it, and the operating system that coordinates resources. Questions often ask you to classify a device or program, identify memory types, or match an OS function to a situation.
Core rules
- CPU components: ALU performs arithmetic/logic, control unit fetches and decodes, registers hold immediate data. Cache is fastest, then RAM, then secondary storage.
- RAM is volatile and holds running programs; ROM/firmware is non-volatile. Secondary storage keeps data without power.
- System software includes the OS, device drivers, utilities and language translators; application software performs user tasks.
- OS functions include process scheduling, memory management, file management, device management, and providing a user interface.
- A GUI uses windows/icons; a CLI uses typed commands. Neither is the OS itself.
Worked example
Classify: Linux, a printer driver, a spreadsheet, and BIOS. Linux is an operating system, hence system software. The printer driver is system software because it lets the OS control hardware. The spreadsheet is application software because it serves a user task. BIOS is firmware stored in ROM, not ordinary application software. The reasoning is based on role, not on whether the program is preinstalled.
Traps
Calling a driver an application is a common error. Cache is not larger than main memory; it is faster and smaller. A GUI is an interface, not a type of application. Turning off power erases RAM contents but not ROM or disk contents. Freeware is about licensing, not about being system software.