Resistance welding is a process used to join two or more pieces of metal by applying heat generated from electrical resistance. During this process, an electric current passes through the metal pieces, creating heat at the contact points. This heat melts the metal, allowing the pieces to fuse together when pressure is applied. There are several types of resistance welding, including spot welding and seam welding. These methods are commonly used in industries such as automotive manufacturing and electronics, where strong, durable joints are essential. The process is efficient and can be automated for high-volume production.