What is the difference between BIOS an firmware?

Answer 1

CMOS is a semiconductor chip of SRAM (Static Random Access Memory); while BIOS is executable code stored in ROM.

The CMOS chip is an ultra low power memory, that can retain its data with only a simple watch type battery for a long time. Computers often store hardware configuration information in CMOS RAM.

BIOS is the programming that a computer uses during power on to get booted. It is also often the interface between the software and the hardware. BIOS used to be stored in read-only memory (ROM), and as such, was unchangeable; but more recently, BIOS is stored on an EEPROM (Electronically Erasable Programmable Read-Only Memory); this allows for the ability to upgrade the BIOS code to provide support for changes in technology, or repair bugs discovered in the older code.

BIOS = Basic Input Output System

CMOS = Complementary Metal-Oxide-Semiconductor

BIOS is the interface which is built-in to a computer system's firmware used to configure the computer system hardware in very basic ways. BIOS can be used to enable or disable hardware integrated into the motherboard such as IDE controllers, USB hosts, audio controllers, video, and more.

It is often accessed by pressing F2 during startup, but this can change from manufacturer to manufacturer.

CMOS is a type of battery often used to power the circuit which allows the information in BIOS to be stored. If the CMOS battery is drained or removed all the system configuration data in BIOS will be reset to factory defaults every time the computer is shut off. CMOS batteries are also commonly used in calculators, hearing aides, and wristwatches.

Due to the close relationship between BIOS and the CMOS battery in the computer system, the two phrases are often incorrectly used as synonyms for each other. Some users will refer to opening the BIOS menu as "going into CMOS" or replacing the CMOS battery as "fixing the BIOS battery." However, none of this is seen as grammatically incorrect in common day-to-day conversation.

Answer 2

By definition there IS no difference between firmware and BIOS. Firmware = software that is permanently stored in a chip. The BIOS on a motherboard of a computer is an example of firmware. BIOS = Basic Input/Output System = Firmware that can control much of a computer's input/output functions, such as communication with the floppy drive and the monitor.