What's: BIOS
The BIOS (Basic Input Output System) is a program in every PC, burned into an EEPROM on the
mainboard.
This way it remains present even after shutdown of the computer and is immediately available after engaging, before the loading of the actual operating system.
After the start, the BIOS executes a self test of the computer and supervises the start activity of the operating system.
The basic settings of the computer, such as the starting order of the data carriers, are also managed in the BIOS.
There are different types of BIOS programs, the outer appeareance and settings look different in almost every computer. Only the basic BIOS functions like self test and system start are identical.
BIOS im deutschen Lexikon
BIOS in het nederlandse encyclopedie