What is the primary function of a capacitor?

The primary function of a capacitor is to store a charge. Capacitors are passive electrical components that can hold an electrical charge temporarily. They consist of two conductive plates separated by an insulating material, known as a dielectric. When voltage is applied across the plates, an electric field is created, allowing the capacitor to accumulate and store electrical energy. This stored energy can be released when needed, which is essential in various applications, including smoothing out fluctuations in power supply, filtering signals in electronic circuits, and timing applications.

While capacitors can play roles in voltage regulation by smoothing out voltage spikes or troughs in certain contexts, the fundamental and most direct role they fulfill is energy storage. This distinguishes their primary function from other components that may focus on regulating, transmitting, or transforming energy in different ways.