Operating System is system software that manages a computer's hardware and software, making it possible for users to interact with the computer.

1. Windows: A popular operating system by Microsoft, used on most PCs.


2. macOS: Apple's operating system for Mac computers, known for its sleek design.


3. Linux: An open-source operating system that is free and customizable.


4. Android: A mobile operating system by Google, used in smartphones and tablets.


5. iOS: Apple's operating system for iPhones and iPads, known for its security and simplicity.