Voltage is the difference in potential electric energy between A and B.
One way to think of voltage is that it is like water pressure in a water pipe.
The pressure on the pipe is the amount of potential energy available to move the water through the pipe. Similarly, voltage is the potential energy available to move electrons trough a conductor.
When you ask about charge, you are inferring a question about current. In the pipe analogy, current would be the water flowing through the pipe, and charge would be the direction of that flow.
Basic Ohm's law states at Voltage (V) = I*R where (I) is current and (R) is resistance. Power (W) also has a place in this algebraic relationship. V=W/I or V=(W*R)2 or...