In welding, polarity refers to the direction that current flow through a circuit. In a direct current electrode positive (DCEP) circuit, the current flows from the workpiece to the electrode. In a direct current electrode negative (DCEN) circuit, the current flows from the electrode to the workpiece. In an alternating current (AC) circuit the two termianls alternate between negative and positive and the direction of the electron flow reverses. See also Direct Current and Circuit.