Frequently Asked Questions - What is the CMOS

CMOS stands for complementary metal oxide semiconductor and is a chip that is powered by a battery and contains the date, time, and system setup parameters for your computer. This information is kept in the memory even when the computer is turned off. That is why when you turn off your computer or unplug it and then turn it back on it remembers the date and time. The other information kept in the CMOS is used by the BIOS for starting up your computer.