How to lay out the answer. Follow the frame, then write it in your own words.
1 · Open in two lines. An operating system is the main system software that manages the computer's hardware and provides services to application programs and users. Examples: Windows, macOS, Linux, Android.
2 · Draw the layers. [Diagram: User → Application software → Operating system → Hardware]
3 · Booting and processor management. It starts the computer (booting) and decides which program uses the CPU, allowing multitasking.
4 · Memory and file management.
Gives RAM to programs and frees it when they close.
Creates, saves, copies and deletes files and folders on storage.
5 · Device management. Controls the keyboard, printer, disks and other devices through device drivers.
6 · User interface and security.
Provides a GUI or command line.
Controls user accounts, passwords and access rights.
7 · Sri Lankan business example. Office desktops run Windows, staff phones run Android or iOS, and antivirus utilities protect the network.
8 · Close in one line. Without an operating system, no application could use the hardware.
Scoring tip: List at least six functions, each with one example.
