We learned three different types of welding, stick, mig, and tig welding.

Stick (arc) Welding- works kind of like the soldering process - you heat up the steel then melt a steel stick into it. The final product was quite sloppy and brittle.

Tig Welding (tungsten inert gas) - it is the most difficult to learn but it is also the cleanest and most controlled.

Mig Welding (metal inert gas) - this is probably the most common type of welding and is the easiest to learn. This one has a steel coil the the machine that feeds into the head.

each type of welding has it's own head.

And they hook up to these machines to get their power.

Before this tutorial, I though welding was prety much just shooting fire at metal to melt it. It actually creates an electrical circuit so it needs to be grounded. The arrows above point to the two different ground conditions (left- stick/tig welding)(right-mig welding)

Here's the steel coil that lives inside the power box and the gas that's used in the process.

Oh and resistance/spot welding. Here it doesn't involve any additional material, it just melts the steel to itself. It's kind of like stapling or sewing.