Basic Input/Output System
BIOS stands for Basic Input/Output System. The BIOS setup program above is used to setup a computer's hardware. Without any disks, or even a hard drive, the BIOS program is always available, written permanently on the BIOS chip. The BIOS chip contains enough information to operate the computer all by itself. When the computer is first turned on, (or booted), the BIOS program is in control. After performing a few system checks, the BIOS program turns the computer over to an operating system like Windows XP.