The motherboard of the computer is essentially the part of the computer that holds all components, each cable from the internal bus connections each connect to the motherboard, the motherboard then connects all the components together with its given technology.
This is a part of the motherboard that basically controls the flow of data throughout the motherboard primarily to and from the computers main memory resource. Memory controllers in a motherboard are basically what decides what memory should be written to the RAM or (DRAM).
The motherboard of the computer has various different ports to allow the connection of all components for the computer. Without this we wouldn't be able to connect the internal devices of our computer together to allow the controllers of the motherboard to flow data throughout the motherboard.
At first it would seem odd for a motherboard to have a battery but the motherboard of computers actually has something called a 'Real Time Clock' (RTC), this is something that allows the motherboard to run and the Real Time Clock is running all of the time whether the computer is on or off, however a battery is required for the Real Time Clock to function.