Computer Science · Chapter 5
Study notes aligned to the official NEB syllabus.
Software is the set of programs, procedures, and data that tell computer hardware what to do. It falls into two categories: system software and application software.
System software runs the machine itself: the operating system, utility programs (disk cleanup, antivirus, file recovery), device drivers, and language translators. A compiler converts the whole source code into machine code at once and reports errors together at the end, an interpreter translates and executes line by line and stops at the first error, and an assembler converts assembly language into machine code.
Application software helps the user do a specific task, for example a word processor, spreadsheet, presentation tool, or database management system. It splits into package software, general purpose and sold to many users (MS Office), and tailored/custom software, built for one organisation (a bank's own transaction system).
| Basis | System software | Application software |
|---|---|---|
| Purpose | Runs and manages the computer | Helps the user do a specific task |
| Dependency | Applications depend on it | Depends on system software to run |
| Examples | Windows, Linux, drivers, compilers | MS Word, Excel, a billing program |
The term "operating system" describes a program that operates the machine on the user's behalf, running the hardware so other programs can load on top of it. An operating system (OS) is a collection of system software that manages hardware resources and provides common services to other programs, acting as an interface between the user and the raw hardware. Windows, Linux, macOS, and Android are all operating systems.
Its core functions: