The equation above is referred to as the power equation. There are two other forms, both of which are derived from ohms law. The separating material is referred to as a dielectric . A capacitor stores energy, unlike the resistor, which consumes energy. When connected across a voltage, the capacitor charges.
Electrons move from one plate of the capacitor and accumulate on the other plate.
Another way to describe this is that the electrons from one side of the capacitor flow through the external circuit under the influence of a voltage, to the other side. If the voltage is steady DC, the capacitor charges to that DC voltage and current flow stops. The voltage across the capacitor is the same as the voltage across the source. The capacitance of a capacitor is a measure of the number of electrons that can move from one side of the capacitor to the other when connected across a given voltage. The example circuit shows a capacitor connected to a battery through a switch and a resistor.