Answer: It is supplied by the welding power source and produces a strong and long-lasting gas discharge phenomenon between the two poles-called arc.
<1>According to the current type, it can be divided into: AC arc, DC arc and pulse arc.
<2>According to the state of the arc, it can be divided into: free arc and compressed arc (such as plasma arc).
<3>According to the electrode material, it can be divided into: melting electrode arc and non-melting electrode arc.