In order to provide thermal energy in welding, there are different devices and methods that provide the required thermal energy with the help of electric arc, electric resistance, gas burning, electron beam, laser beam, friction between parts, ultrasound waves. Therefore, according to the type of heat source supply, there are wide welding methods.  On the other hand, it is necessary to use filler metal in welding with the purpose of repair, coating and in joint welding with a large gap between parts. Depending on the welding method, filler metal can be welding wire, wire filler, powder, etc. In some methods that provide thermal energy by burning gas, gas is used as a consumable. In other welding methods, it is recommended to protect the weld by using shielding gas. Other equipment such as robots and fixtures are used to automate and facilitate the welding process.