What is the main purpose of a capacitor in a circuit?

The main purpose of a capacitor in a circuit is to store electrical energy. Capacitors are passive electronic components that can accumulate charge on their plates when a voltage is applied across them. This charge can be released when needed, which allows capacitors to provide energy to the circuit at different times, smooth out voltage fluctuations, and filter signals. The ability to store energy temporarily is crucial in various applications, such as power supply systems, where they help manage energy during fluctuations or interruptions.

This energy storage capability distinguishes capacitors from other components like resistors or inductors, which primarily either impede current flow or influence magnetic fields, respectively. Thus, the role of a capacitor as a storage device is fundamental to its function in many electrical and electronic circuits.