Fusing together is a process of combining two or more materials into one. Welding, melding, coalescing, and blending are all methods of fusing together. Welding is a process of joining two pieces of metal together by melting them and then cooling them. Melding is a process of combining two or more materials together by melting them and then cooling them. Coalescing is a process of combining two or more materials together by using pressure and heat. Blending is a process of combining two or more materials together without the use of heat or pressure. All of these processes are used to fuse together materials to create a single, unified product.