 Short for Basic Input/Output System, BIOS is a chip located on all computer motherboards that contains instructions and setup for how your system should boot and how it operates. To the right is a picture of what a BIOS chip may look like in your computer.
The BIOS includes instructions on how to load basic computer hardware and includes a test referred to as a POST (Power On Self Test) that helps verify the computer meets requirements to boot up properly. If the computer does not pass the POST, you will receive a combination of beeps indicating what is malfunctioning within the computer. In most PCs, the BIOS has 4 main functions: POST - Test computer hardware, ensuring hardware is properly functioning before starting process of loading operating system. Additional information
on the POST can be found on our POST / Beep Codes page. Bootstrap Loader - Process of locating the operating system. If capable operating system located, BIOS will pass the control to it. BIOS - Software / Drivers that interface between the operating system and your hardware. When running DOS or Windows you are using complete BIOS support. BIOS / CMOS Setup - Configuration program that allows you to configure hardware settings including system settings such as computer passwords, time, and date.
Also see: ACPI, BIOS shadow, BPB, CMOS, EFI, Firmware, Flash BIOS, Motherboard definitions | 
