What role does a capacitor play in an electrical circuit?

A capacitor plays a critical role in an electrical circuit by storing and releasing electrical energy. Capacitance allows the capacitor to accumulate charge when a voltage is applied, effectively storing electrical energy in an electric field between its plates. When the voltage across the capacitor is removed or changes, the stored energy can be released back into the circuit, providing a source of electrical energy when needed.

This ability to store and release energy is fundamental in various applications, such as smoothing out fluctuations in power supply in power electronics, filtering in signal processing, or providing bursts of energy in timing circuits. This characteristic distinguishes capacitors from other components that may continuously generate energy or convert energy types.