An ampere hour or amp hour is a unit of electric charge equal to the charge transferred by a current of one ampere flowing for one hour, or 3600 coulombs. The commonly seen milliampere hour (mAh or mA·h) is one-thousandth of an ampere hour (3.6 coulombs).
It is used as the amount of charge that can be storede inside a battery.
An ampere is a unit of measure of the rate of electron flow or current in an electrical conductor. One ampere of current represents one coulomb of electrical charge (6.24 x 1018 charge carriers) moving past a specific point in one second.