Just like a mass falls from a place where it has a higher potential energy, an airplane or someplace in the universe, to where it has a lower potential energy, the ground or a different place in the universe, so do charges. Charges will always go to where they have lower electric potential or potential. This going is also called "falling'. A group of charges or a charged object will fall from where there is an electric potential of 10 joules per coulomb to where there is an electric potential of 5 joules per coulomb, or from a place with an electric potential of 10 volts to one with an electric potential of 5 volts. If there are 20 coulombs of charge on an object, it will fall from having an electric potential energy (EPE) of 200 joules (20 c x (10 j/c) = 200 joules) at the place with an electric potential of 10 volts to an an electric potential energy of 100 joules (20 c x (5 j/c) = 100 joules) at the place with an electric potential of 5 volts.