BIOS refers to basic input/output system (BIOS). BIOS software is built into the PC, and is the first code run by a PC when powered on, and that is why it is called boot firmware.
In computing, firmware is software that is embedded in a hardware device. It is often provided on flash ROM or as a binary image file that can be uploaded onto existing hardware by a user. When we turn on the power switch, computer will make some beeps while it goes through a self-check of the system components. If we want to change any of the setup options, such as setting a password for the system, changing the sequence for booting up the computer., or reconfiguring any other hardware, we need to press the F2 or any other key recommended by the hardware provider to access the key BIOS settings.
The BIOS includes very basic information about the hardware to get the computer started before the operating system software takes over. Once the operating system takes over, more detailed information about the hardware is loaded into the computer’s RAM and windows starts up.
Thus, primary function of the BIOS is to set up the hardware and load and start an operating system. When the PC starts up, the first job for the BIOS is to initialize and identify system devices such as the video display card, keyboard and mouse, hard disk drive, optical disc drive and other hardware. The BIOS then locates software held on a peripheral device (‘boot device’), such as a hard disk or a CD/DVD, and loads and executes that software, giving it control of the PC. This process is known as booting. Booting is synonymous with a booting up, which is short for bootstrapping.