Welding is a process of joining two or more pieces of metal together by melting and fusing them. The term 'WELD' is used to describe the process of joining two pieces of metal together, while the term 'FUSE' is used to describe the actual joining of the two pieces of metal. Fusing is a common welding technique that involves melting and combining two pieces of metal together. This process is often used in the construction of buildings, bridges, and other structures.