What are the kinds of welding?

There are a considerable number of welding processes that cover a vast range of metals and some nonmetals in most industries and applications. An Excellent resource for welding information is The American Welding Society (AWS.org). A short list of the most common processes are: Oxygen Fuel Gas (OFG) which includes welding and cutting equipment where oxygen is mixed with a fuel gas such as acetylene, propane, etc. and a torch is used. Shielded Metal Arc (SMAW) sometimes called "Stick Rod" welding. This is a manual process that uses a flux covered wire electrode that melts during welding to form the filler metal. Gas Metal Arc Welding (GMAW) sometimes called "MIG" (for Metal Inert Gas) which is a semi automatic process that uses a bare or flux cored wire that is delivered by a spool drive during welding. Gas Tungsten Arc Welding (GTAW) sometimes called "TIG" (for Tungsten Inert Gas) or Heiliarc (trade name by the Lindy corp.) which uses a non consumable Tungsten electrode in an inert gas shielded gas torch. The Tungsten's produces the heat (via an electric current) and filler metal is added by "dipping" the tip of a bare wire to the weld puddle. The list goes on to include things like Electron Beam Welding , Plasma Arc Welding / Cutting, Friction Welding, Explosion Welding. Microwave Welding, Plastic Welding, etc.. Welding is used on everything from auto mufflers to space vehicles and medical instruments.