An operating system (OS) is system software that manages computer hardware and provides a platform for applications. This topic covers OS functions, types, file management basics, and the difference between GUI and CLI.
The OS is the most important software — it starts when you turn on the computer and manages everything. Functions: (1) hardware management, (2) file management (organising files in folders), (3) memory management, (4) process management (running programs), (5) providing user interface. Examples: Windows 11, macOS, Ubuntu Linux, Android (mobile), iOS (iPhone).
GUI (Graphical User Interface): uses icons, windows, menus — easy to use (Windows, macOS). CLI (Command Line Interface): text commands — more powerful (Terminal, Command Prompt). File management: files stored in folders (directories). Path: C:\Users\Documents\homework.pdf. Operations: create, copy, move, rename, delete files and folders.
Without an OS, you would need to communicate directly with hardware using machine language — practically impossible for daily use. The OS acts as an intermediary: it manages hardware, provides a user-friendly interface, runs applications, manages files, and ensures multiple programs can run without conflicting. It is the foundation on which all other software runs.
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