AC:
It stands for Alternating Current. It is an electric current that changes periodically the direction and amplitude constantly. Alternating current is following in both the direction and with time domain the magnetic of current is changing continuously.
DC:
It stands for Direct Current. It is a current that is flowing in one direction only and which doesn’t have any appreciable pulsating in its magnitude. In a direct current, the direction of current flow is always the same.