Answer:
The BIOS (Basic Input/Output System), also known as firmware, is basically software that's permanently recorded on a chip that sits on the motherboard. The BIOS plays two critical roles in the operation of your PC: It provides the instructions needed to start a PC, and it interfaces the PC's hardware to your OS (operating system).
Each time you start a PC, the BIOS provides the instructions needed to initialize and test the major hardware components before an OS starts to load. The OS cannot perform POST (power on self test) procedures because of the huge diversity in PC hardware, so one purpose of the BIOS is to specifically address the particular components of a given PC. Once the hardware "passes" the POST, control transfers to the OS, which then loads and presents its Desktop on-screen.
OSes don't operate hardware directly; there are simply too many hardware devices (such as chips and drives) for the OS to accommodate. Instead, an OS performs certain low-level functions by accessing standard routines in the BIOS. The BIOS provides a standard suite of functions tailored for the PC's particular group of hardware. That way, one OS can operate on many hardware platforms using the BIOS as an interface. |