Welding machines are tools used to join materials, typically metals, by applying heat and pressure. They work by melting the edges of the materials to be joined, allowing them to fuse together as they cool. Common types of welding machines include MIG (Metal Inert Gas), TIG (Tungsten Inert Gas), and Stick welding machines, each suited for different applications and materials. These machines can be powered by electricity, gas, or other energy sources, and they come in various sizes for different tasks. Welders often use protective gear, such as helmets and gloves, to ensure safety while operating these machines.