What does a capacitor store as it charges to the source voltage?

A capacitor stores energy as it charges to the source voltage. When a capacitor is connected to a voltage source, it accumulates electric charge on its plates, which results in the creation of an electric field between them. The amount of energy stored in a capacitor can be calculated using the formula (E = \frac{1}{2}CV^2), where (E) is the energy, (C) is the capacitance, and (V) is the voltage across the capacitor. This energy can be released back into the circuit when needed, making capacitors essential components in various applications, such as smoothing out voltage fluctuations, filtering, and timing circuits.

The other options do not accurately describe what a capacitor stores: it does not store electricity in the conventional sense of continuous flow, nor does it store magnetism, which is associated with inductors. Power, which is the rate of energy transfer, also does not represent what the capacitor holds while charging. Instead, energy is the correct term to describe what is being stored during this process.