Short for Basic Input/Output System, the BIOS (pronounced bye-oss) is a ROM chip found on motherboards that allows you to access and set up your computer system at the most basic level. The picture below is an example of what a BIOS chip may look like on a computer motherboard.

Is BIOS part of ROM?

Originally, BIOS firmware was stored in a ROM chip on the PC motherboard. In modern computer systems, the BIOS contents are stored on flash memory so it can be rewritten without removing the chip from the motherboard.

What is BIOS and which type of ROM it is?

A computer’s basic input/output system (BIOS) is a program that’s stored in nonvolatile memory such as read-only memory (ROM) or flash memory, making it firmware. The BIOS (sometimes called ROM BIOS) is always the first program that executes when a computer is powered up.