TIG (Tungsten Inert Gas) welder is a type of welding machine that uses an electric arc to fuse metal parts together. It works by creating an arc between a tungsten electrode and the workpiece, while a shielding gas, typically argon or helium, is used to protect the welding area from contamination.

MIG welder, also known as a metal inert gas welder, is a type of welding machine that uses a wire electrode to create an electrical arc that melts and fuses metal together. The wire electrode is fed through a spool and a welding gun, and is continuously melted and deposited onto the workpiece as the welding process progresses.

A plasma cutter is a tool used to cut various materials, including metal, steel, and other conductive materials. It works by creating a high-temperature plasma arc, which is used to melt and cut through the material. The plasma cutter uses an electrical arc to ionize gas, typically compressed air, and then heats the ionized gas to a very high temperature, producing a plasma jet that can be directed onto the material being cut.