A welding machine, also known as a welder or welding power supply, is a device used to join materials, typically metals, by creating a strong bond through the application of heat. It works by melting the edges of the materials and allowing them to cool and fuse together. Welding machines come in various types, such as arc welders, MIG welders, TIG welders, and more, each suited for specific applications and materials. These machines are widely used in construction, manufacturing, automotive, and other industries to create strong and durable connections between metal components.