1.BIOS - Basic Input/Output System. A set of routines that works with a computer system's hardware to support data transfers between the various components, such as the monitor and disk drives, of a system.
2.BIOS Basic Input Output System. The part of the system software of the PC that provides the lowest level interface to peripheral devices and controls the first stage of the start up process, including installing the operating system. The BIOS is stored in ROM or equivalent, in every PC. Its main task is to load and execute the operating system which is usually stored on the computer's hard disk, but may be loaded from CD-ROM or floppy disk at install time.
System Software Software is generally divided into systems software and applications software. System software is the operating system and all utility programs that manage computer resources at a low level.
3.BIOS - An acronym for Basic Input/Output System. The BIOS is built-in software that determines what a computer can do without accessing programs from a disk. On PCs, the BIOS contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions. The BIOS is typically placed in a ROM chip that comes with the computer (it is often called a ROM BIOS). This ensures that the BIOS will always be available and will not be damaged by disk failures. It also makes it possible for a computer to boot itself. Many modern PCs have a flash BIOS, which means that the BIOS has been recorded on a flash memory chip, which can be updated if necessary. The PC BIOS is fairly standardized, so all PCs are similar at this level (although there are different BIOS versions). Additional DOS functions are usually added through software modules. This means you can upgrade to a newer version of DOS without changing the BIOS.
4.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 video display card, hard disk, and floppy disk and other hardware. This is to prepare the machine into a known state, so that software stored on compatible media can be loaded, executed, and given control of the PC.[3] This process is known as booting, or booting up, which is short for bootstrapping.
Firmware
The first set of machine instructions to run on the hardware after the application of power.
