What is the Difference Between BIOS and CMOS?

Typically the CMOS (complimentary metal oxide semiconductor) and the BIOS (basic input/output system) are often confused sometimes due to instructions either indicating to enter the CMOS Setup or the BIOS Setup. Despite the fact that the setup for the CMOS and the BIOS are the same; the CMOS and the BIOS on the motherboard aren't.

The CMOS and the BIOS are in fact two separate components on the motherboard. The CMOS is powered by a battery and holds system settings and is customized and altered by entering the CMOS Setup and making changes. However, the BIOS on the motherboard holds the instructions on how the computer boots-up and is only updated or changed when updating the BIOS.

Despite being referred to as the BIOS/CMOS setup, it is correctly and more aptly referred to as just the CMOS setup.