What are the applications of a capacitor?

A capacitor is a device that stores electric potential energy and charge. Unlike batteries, capacitors do not involve chemical reactions. They merely encompass the movement of charged particles, so they can be charged and discharged very quickly. This important property gives them many useful applications.

They are used as electrical flash units in Photography, lasers, air bag sensors, radio receivers, and television receivers. Most importantly, they are used in alternating-current circuits, which play a crucial role in most household and industrial power-distribution systems.