What does a capacitor do in an electrical circuit?

A capacitor functions primarily as a device that stores electric charge in an electrical circuit. It consists of two conductive plates separated by an insulating material, known as a dielectric. When voltage is applied across the plates, an electric field is established, allowing the capacitor to store energy in the form of an electric charge. This ability to store and release energy quickly makes capacitors essential in various applications, such as smoothing out voltage fluctuations, filtering signals, and in timing circuits.

Understanding the role of a capacitor can also illuminate other concepts in electronics. For instance, capacitors can release stored energy when needed, providing a quick burst of current to help stabilize power in circuits. This is why they are often found in power supply systems in vehicles to smooth out any irregularities in voltage or current flow.