MIG and MAG welding equipment is typically comprised of a power source, wire feeder, grounding cable, welding gun, optional liquid cooling unit and a shielding gas bottle or gas network connection.

The purpose of the wire feeder is to feed the welding wire needed in welding from the wire reel to the welding gun. 

The wire feeder also allows for starting and stopping the power source and, when using an electronic power source, control the voltage provided by the power source. Therefore the power source and the wire feeder are connected with a control cable. Additionally, the wire feeder controls the flow of the shielding gas. The shielding gas needed in welding is obtained either from a gas bottle or from a gas network.

The welding gun heats up during welding, and therefore it must be cooled with gas or liquid. In gas-cooled welding guns, the shielding gas running to the gun through the welding cable simultaneously acts as the gun cooler. In liquid-cooled guns, a separate liquid cooling unit is required to recycle the cooling liquid within the welding cable to the gun.