BIOS is Basic Input Output System
it is a boot program "burned" on an EPROM - Erasable Programmable Read Only Memory chip on your motherboard. It tells your motherboard how to boot up and general configurations.
Essentially it is a mini-program stored on a chip. Without it, your computer is a giant paperweight. The computer needs BIOS to know where to boot up and turn on devices BEFORE your operating system takes over.
manufactuers often update BIOS for compatibility issues. go to the manufactuer's website and download the latest BIOS and update program.
you need a REAL floppy drive attached to your motherboard to do this right. BIOS updates are core system alterations that is done on the most primitive level. Since all intel/amd motherboards are based on intel 8086 technology at their central core, a floppy is required. It is foolish to have a computer without one, even if you never use it. This is one area where it is required. I do not recommend BIOS updates from a CD rom. There are many issues that can arise.