The BIOS is a small program that controls the computer from the time it powers on until the time the operating system takes over. The BIOS is firmware, and thus cannot store variable data. CMOS is a type of memory technology, but most people use the term to refer to the chip that stores variable data for startup.

Is BIOS part of the operating system?

The BIOS, literally a “basic input/output system”, is a set of small programs hard-coded into a computer’s motherboard (usually stored on an EEPROM). … By itself, the BIOS is not an operating system. The BIOS is a small program to actually load an OS.

What is the CMOS in a computer?

Complementary metal-oxide-semiconductor (CMOS) is a small amount of memory on a computer motherboard that stores the Basic Input/Output System (BIOS) settings.