An AC circuit is an electrical circuit that uses alternating current, where the flow of electric charge periodically reverses direction. This type of current is commonly found in household power supplies, allowing appliances to operate efficiently. The voltage in an AC circuit also varies sinusoidally, which means it fluctuates in a wave-like pattern over time. AC circuits can be simple or complex, consisting of components like resistors, capacitors, and inductors. These components interact with the alternating current in different ways, affecting the circuit's overall behavior. Understanding AC circuits is essential for designing and troubleshooting electrical systems in homes and industries.