MIG welding is a form of arc welding, with MIG being an abbreviation for metal inert gas. The inert gas this refers to is used to shield the weld pool from contamination by the atmosphere, which can compromise the strength and surface finish of the weld bond. Arc welding melts and fuses two workpieces together using the heat from an electrical arc - MIG welding uses a consumable electrode within this process, that melts and forms part of the weld bond.
MIG welding is generally suited to thicker materials of approximately ½" thick. It is also a relatively fast process within the arc welding subset; however, it is not as capable of facilitating the level of precision as its counterparts. In addition, weldments produced by MIG welding may not be as strong as those produced via TIG welding.
MIG welding can be used on a variety of materials such as aluminium, copper, stainless steel and carbon steel.