TIG Welding, also known as Gas Tungsten Arc Welding (GTAW), is a process that includes the use of an electric arc combined with a TIG electrode. The electrode itself is made out of tungsten, meaning that it does not dissolve when welding. Old-timers used to refer to this method as Heliarc welding because they used helium as a shielding gas.
The process itself includes a non-consumable tungsten electrode that carries current to the welding arc.
Both the weld pool and the tungsten are shielded using an inert gas (usually pure argon gas). This type of process is comparable to oxy-acetylene welding because both of them use filler material for reinforcement.
TIG welding is a process that requires the welder to use both arms. One hand holds the TIG torch while the other adds the filler rod to the weld joint. This makes TIG welding the most difficult process to learn. But after learning it, it becomes the most useful process that one can acquire due to its versatility.
Types of materials that you can weld include steel, stainless steel, aluminum, nickel alloys, chrome alloys, copper, and brass. magnesium, bronze, and even gold.
The process is slow, but when done right it provides the most beautiful weld, aesthetically speaking, and a high-quality one as well.