BIOS
Acronym for basic input/output system. In the PC, a set of instructions, stored in read-only memory (ROM), that let your computer's hardware and operating system communicate with application programs and peripheral devices such as hard disks, printers, and video adapters. These instructions are stored in non-volatile memory or as a permanent part of your computer. They are always available at a specific addresses in memory, so all programs can access them to perform their basic I/O functions.
IBM computers contain a copyrighted BIOS that only their computers can use; however, other companies such as Phoenix, Award, and American Megatrends have developed BIOSes for other manufacturer's computers that emulate or mimic the IBM instructions without using the same code. If you use non-IBM computer, the BIOS company's copyright message and BIOS version number are displayed every time you turn on your computer.