The capacitance 'C' is a measure of the capacitor's potential to store energy in:

A capacitor is a two-terminal energy storage device that stores energy in the form of a static electric field during the positive half cycle and gives away during the negative half cycle of supply.

The energy spent in charging a capacitor of capacitance C to a Potential applied E is given by:

C = Capacitance of the capacitor

E = Potential applied across the capacitor