What is an operating system?
An operating system (OS) is system software that manages computer hardware and provides services that applications use.
Examples include Windows, macOS, Linux, Android and iOS.
Main jobs of an operating system
Process management
Helps manage programs and CPU time.
Memory management
Allocates and manages memory for programs.
File management
Organizes files and folders on storage devices.
Device management
Coordinates hardware such as keyboards, displays and printers.
Security
Provides accounts, permissions and other protection mechanisms.
User interface
Provides graphical or command-line ways to interact with the computer.
System software vs application software
The operating system is system software. A word processor, browser or drawing app is application software. Applications rely on the operating system to access many hardware and system services.