What is typically a function of the CMOS battery in a computer?

The function of the CMOS battery in a computer is primarily to store BIOS settings. This battery powers the Complementary Metal-Oxide-Semiconductor (CMOS) chip, which holds essential configuration data, including system time, hardware settings, and various BIOS configurations. When the computer is turned off, the CMOS battery ensures that these settings are retained, allowing the system to boot up with the correct parameters each time it powers on.

The other functions listed are not related to the role of the CMOS battery. The CPU is powered by the main power supply of the system, not by the CMOS battery. Similarly, the hard drive has its own independent power supply and storage mechanism, and it does not rely on the CMOS battery for backup. Peripheral devices also operate under their own power sources or the main supply, not the CMOS battery. Thus, the correct answer highlights the specific and critical role of the CMOS battery in maintaining BIOS settings.