MIG can be applied to a wide variety of metals, both ferrous and non-ferrous,including mild and stainless steels and aluminium.
Welding speeds are greater for MIG than for TIG or MMA which is of benefit if welding is a frequent or continuous occurrence.It is also well suited to production welding.Further,the arc size for MIG is generally small (compared to say MMA) so it lends itself well to precision work.
The equipment required to perform MIG welding is more complex than stick welding and the need for a gas bottle may make the process unviable for some off-site work.
The gas used in MIG welding process depends on the type of material being welded. For non-ferrous materials such as aluminium,the gas tends to be pure argon.For ferrous materials the gas will typically be argon mix (inc CO2).