What is the basic Input output system is stored on?

Answer 1

The BIOS is boot firmware, designed to be the first code run by a PC when powered on. The initial function of the BIOS is to identify, test, and initialize system devices such as the Display Card, HDD, FDD and other hardware. The BIOS sets the machine hardware into a known state, so that Software stored on compatible media can be loaded, executed, and given control of the PC. This process is known as booting, or booting up, which is short for Bootstrapping.

The role of BIOS has changed over time; today BIOS is a legacy system, superseded by the more complex Extensible Firmware Interface (EFI), but BIOS remains in widespread use, and EFI booting has only been supported in x86 Windows since 2008. BIOS is primarily associated with the 16-bit and 32-bit architecture eras (x86-32), while EFI is used for some 32-bit and most 64-bit architectures. Today BIOS is primarily used for booting a system, and for certain additional features such as power management (ACPI), but otherwise is not used during the ordinary running of a system, while in early systems (particularly in the 16-bit era), BIOS was used for hardware access - operating systems (notably MS-DOS) would call the BIOS rather than directly accessing the hardware. In the 32-bit era and later, operating systems instead generally directly accessed the hardware using their own device drivers.