PC motherboard battery

What is a computer motherboard battery, what kind of role the computer is anything wrong with the computer motherboard inside the battery problems caused by? Please understand computers

1, the role of the motherboard battery is closed, continue to supply BIOS to preserve the BIOS settings.
2, no battery power after motherboard BIOS settings can not be preserved, but the general will return to the default BIOS settings And this set is not caused by computer failures.1.Motherboard bios to preserve the information,
2.Shutdown can not be retained after the resumption of the board settings.Called the CMOS battery, the BIOS used to record information.Likely to cause problems For example, computer time will not be allowed to re-boot, and so on.BIOS RAM for the role of electricity in order to preserve the basic settings in general.
Wrong time, such as computers, cell board is caused by