The working principle of a capacitor is to store electrical energy by storing charge on the electrode, and is usually used together with an inductor to form an LC oscillation circuit. The working principle of the capacitor is that the electric charge will move under the force in the electric field. When there is a medium between the conductors, the electric charge will be prevented from moving and the electric charge will accumulate on the conductor, resulting in the accumulation of electric charge.
Capacitors are one of the most widely used electronic components in electronic equipment, so they are widely used in dc blocking, coupling, bypass, filtering, tuning loops, energy conversion, control circuits, etc.