Welding is simply using electricity to melt metal together. Simple as that, nothing more nothing less.

Mig welding is called "Metal In Gas" welding. In the early days it was called "Metal Inert Gas" welding. But some gases that you use in the mig welding process will actually not be "inert".

Some gases will actual be the opposite which is "active". So now there is also another name and that is MAG welding or "Metal Active Gas" welding.

But in general it's just mig welding.

Next.....

The biggest thing that makes a mig welder a mig welder is that you hold onto a mig welding gun. The MIG welding gun or welding torch feeds the electricity needed to weld. It feeds the shielding gas needed to weld and it also feeds the mig welding wire to the weld.

When mig welding with a mig welding gun, all you do is "in a nut shell" pull the trigger and away you go.

Simple. Mig welding is the easy way to weld.

Arc Welding is still using electricity. But this time there is no shielding gas, and there is no constant feeding of mig welding wire into the weld.

When arc welding you will use a welding rod or welding electrode. On the welding electrode there is a coating of flux. When you weld, this "flux" will burn off and create the shielding gases needed to weld.

Like in MIG welding you need a shielding gas, with arc welding or also know as SMAW (Shielded Metal Arc Welding), you still need a protective gas to weld. This is how it is done with stick welding by using the flux coating on a welding rod.

You can MIG weld mild steel, stainless steel, aluminum, high tensile steels, etc. And you can arc weld mild steel, stainless steel, high tensile steels as well.