AC vs. DC

AC - Alternating Current

Alternating current refers to current that changes direction. If you could watch electrons being moved by an alternating current in a wire you would see them bouncing back and forth. Alternating Current is always associated with a frequency, that frequency is how often the direction of current changes. For example, household electricity is an alternating current that switches direction at a rate of 60 hertz (Hz) or 60 times per second.

DC - Direct Current

Direct Current is much simpler. It is a current that does not change direction, instead it keeps electrons constantly flowing in the same direction.