What is the Basic Input Output System (BIOS)?

BIOS is an acronym for Basic Input Output System. It is the program that stores configuration details about your computer hardware and enables your computer to boot up. Every time your computer is switched on the BIOS loads configuration data into main memory, performs a routine diagnostic test on your hardware, then loads the operating system. The BIOS resides in a ROM (Read-Only memory) chip, which is mounted on the motherboard, usually in a socket so it is removable.To the right is an example of what a BIOS chip may look like in your motherboard. This is a PLCC 32 pin type BIOS chip. It is a very common type.