What does a capacitor do in an electrical circuit?

A capacitor is a component in electrical circuits that plays a crucial role in storing and releasing electrical energy. When a voltage is applied across its terminals, the capacitor accumulates an electric charge. This stored energy can then be released back into the circuit when needed, making capacitors essential for various applications such as smoothing out voltage fluctuations, filtering signals, and providing power to devices during brief interruptions in voltage supply.

This energy storage capability is what differentiates capacitors from other circuit components. While amplifiers enhance signal strength and regulators control current flow, these are not functions of a capacitor. Similarly, the conversion of alternating current (AC) to direct current (DC) is typically handled by rectifiers, not capacitors. Therefore, the function of storing and releasing electrical energy is accurately represented by the selected answer.