AC Circuits refer to electrical circuits where the current alternates direction periodically. Unlike DC Circuits, where the current flows in one direction, AC allows for efficient power distribution over long distances. This is primarily due to the ability to easily transform voltage levels using transformers, making it suitable for residential and industrial use. In an AC circuit, the voltage and current can be represented as sinusoidal waves, characterized by their frequency, measured in hertz (Hz). Commonly, household electricity operates at a frequency of 60 Hz in the United States and 50 Hz in many other countries. This alternating nature enables the use of various electrical devices and appliances.