It uses bare wire used to join metal and second the flux core which is used outdoor because it doesn’t need gas supply. This type is for hobby ones.
It has a stick electric welding rod. It is harder than the previous one.
This one is very adaptable, but also a very difficult one.
Plasma Arc Welding
This is a very much accurate one and similar to TIG welding. It is commonly used in aerospace applications where the metal thickness is 0.015 of an inch. The electrode is recessed and the ionizing gases inside the arc are used to create heat.
Electron Beam and Laser Welding
It is not used and replaced by TIG welding. It needs oxygen and acetylene