Question: I need a definition and explanation for the CMOS.
Answer: CMOS stands for Complementary metal Oxide Semiconductor. This type of circuitry only requires a very small amount of power to operate and so is used within computers to store information about the computer configuration and the current time. A battery keeps this circuitry operational even when the computer is turned off and unplugged.
This article written by Stephen Chapman, Felgall Pty Ltd.