Welding guns are tools used in welding to deliver an electric current to create an arc between an electrode (usually made of metal wire) and the workpiece. The heat from the arc melts the electrode and the workpiece, which fuse together to form a strong, permanent bond.

There are several types of welding guns, each with its own specific uses and advantages:

1. MIG (metal inert gas) welding guns: MIG welding guns are commonly used in automotive and manufacturing industries. They use a spool of wire that is continuously fed through the gun and an inert gas (usually argon or helium) to shield the weld from contamination.

2. TIG (tungsten inert gas) welding guns: TIG welding guns are commonly used for precision welding, especially in the aerospace and medical industries. They use a tungsten electrode and a separate filler rod, which are both fed into the weld by the operator. An inert gas (usually argon) is used to shield the weld.

The choice of welding gun depends on the type of material being welded, the thickness of the material, the desired quality of the weld, and other factors. It is important to select the appropriate welding gun for the job in order to achieve a strong and reliable weld.