Volts and amperes explained
Current is the charge passing a particular point per time.  The common unit of Ampere is one Coulomb of charge passing by per second.

EMF (electromotive force) is the push that makes charges flow.  You can think of it a pressure that pushes charges and causes current to the extent that the charges can move.  A common unit of measure is the volt.  One volt can push one ampere of current thru a resistance of one ohm.