What does BIOS do when the computer is booting?

BIOS (basic input/output system) is the program a computer’s microprocessor uses to start the computer system after it is powered on. It also manages data flow between the computer’s operating system (OS) and attached devices, such as the hard disk, video adapter, keyboard, mouse and printer.

What are the 4 functions of BIOS?

The BIOS has 4 main functions: POST – Test computer hardware insuring hardware is properly functioning before starting process of loading Operating System. Bootstrap Loader – Process of locating the operating system. If capable Operating system located BIOS will pass the control to it.