BIOS is an acronym for Basic Input/output System. It is basic firmware that is run during boot up to initialize hardware. It is what is responsible from loading the operating system from a mass storage device. Most people having limited experience with BIOS and it usually only when they need to access and change setting in the BIOS menu. The BIOS menu is typically a blue and grey screen accessed by pressing F2 or F10 while the computer is booting. Bios is typically stored in flash memory located on the motherboard. This allows it to be updated, but also can end with a bricked motherboard if the bios firmware update fails. Because of some of the shortcomings there is a replacement for BIOS. It is called UEFI which stands for Unified Extensible Firmware Interface.

BIOS