A BIOS (Basic Input/Output System) is an electronic set of instructions stored in EPROM and used by the CPU to perform start-up procedures when the computer is turned on. It is located on the chip inside of the computer and is designed in such a way that protects it from disk failure.
There are two main function of BIOS: One to
determine what computer peripheral devices (keyboard, mouse, disk drives, printers, video cards, etc.) are available and
second to load the operating system (OS) onto the main memory. As the
computer started BIOS gives the instructions for the POST
(Power-On-Self-Test). This self test ensures that all the required computer
peripheral devices are attached in the right way and all the necessary
functionality parts are working correctly. if BIOS detects any
sort of errors during POST, it instructs the computer to give a code that reveals the problem.
The sound of beeps begin to ring in a series to indicate the errors.
Besides these the BIOS also instruct the users how to interact with some critical components like drives and memory, by giving basic information necessary for loading the operating system. BIOS allows the users to make some certain adjustments in itself through a configuration screen on the computer. As soon as, the system turn on, the user can access the setup screen through using a special key sequences. The users can change in the order in which drives are accessed during startup and controlling functionality of a number of critical devices. The Features of BIOS versions may vary to the personnel computer system.
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