See STANDARD WELDING TERMS. See also WELDING ARC.
An electric arc is formed when two conductors of an electric circuit are brought together forming electrical contact, then separated, with sufficient voltage available to maintain the current of electricity through the intervening gaseous medium.
In a continuous current arc, the conductor from which the current flows is called the positive electrode, or anode. The conductor to which the current flows is called the negative electrode, or cathode. The heated gases are sometimes called the arc flame, or the arc plasma.