Welding is a process of joining metals by heating.
Today, there are many welding processes available.
Welding methods uses gas as a source of heat.
Shielded Metal Arc Welding (SMAW)
Shielded metal arc welding is performed by striking an arc between a coated-metal electrode and the base metal.
Gas Shielded Arc Welding
The primary difference between shielded metal arc welding and gas shielded arc welding is the type of shielding used. In gas shielded arc welding, both the arc and the molten puddle are covered by a shield of inert gas ie helium, argon, or carbon dioxide.