1. A BIOS is a small program that controls a personal computer's hardware from the time the computer is started until the main operating system (e.g., Linux, Mac OS X or MS-DOS) takes over.
, 2. BIOS is a type of firmware used to perf … 2. BIOS is a type of firmware used to perform hardware initialization during the booting process (power-on startup) on IBM PC compatible computers, and to provide runtime services for operating systems and programs.BIOS firmware is built into personal computers (PCs),and it is the first software they run when powered on.e first software they run when powered on.