Sheet metal welding is a process of joining thin sheets of metal by applying heat and pressure. There are different methods of sheet metal welding, such as MIG, TIG, stick, plasma arc, electron beam, laser, and gas welding. Each method has its advantages and disadvantages depending on the type of metal, the thickness of the sheet, the desired shape and quality of the weld, and the equipment and skill required. Sheet metal welding is used for various applications in industries such as automotive, aerospace, construction, and electronics.