What is a capacitor used for in electrical circuits?

A capacitor is primarily used in electrical circuits to store electrical energy temporarily. It functions by accumulating voltage across its plates when a potential difference is applied. This storage allows capacitors to release the stored energy rapidly when needed in the circuit, providing a brief surge of power. This property is particularly valuable in various applications such as smoothing out fluctuations in power supply, filtering signals, and providing stability in power systems.

The ability of capacitors to charge and discharge quickly makes them essential for tasks like decoupling, where they help to isolate different parts of a circuit, and in timing applications where they can help create delays. Additionally, in audio and communication systems, capacitors can filter unwanted frequencies, thus enhancing performance. Overall, the role of a capacitor as a temporary energy storage device is fundamental in both simple and complex electrical circuits.