The operating system (OS) is the program which starts up when you turn on your computer and runs underneath all other programs - without it nothing would happen at all.
In simple terms, an operating system is a manager. It manages all the available resources on a computer, from the CPU, to memory, to hard disk accesses.
Tasks the operating system must perform:
- Control Hardware - The operating system controls all the parts of the computer and attempts to get everything working together.
- Run Applications - Another job the OS does is run application software. This would include word processors, web browsers, games, etc...
- Manage Data and Files - The OS makes it easy for you to organize your computer. Through the OS you are able to do a number of things to data, including copy, move, delete, and rename it. This makes it much easier to find and organize what you have.