Alternating current (AC) is the kind of electricity that is used in most homes. AC electricity is special because it has the ability to change direction very quickly. That means that it can move through wires in different directions (from positive to negative, and negative to positive) 60 times a second. AC electricity also has the ability to change its strength very quickly, making it perfect for powering our homes. AC electricity helps to power our lights, televisions, computers, and fans!