Three-dimensional (3D) printing, also known as additive manufacturing (AM), is a production technique that produces three-dimensional parts. In this process, materials are added gradually, layer by layer to the part. Metal and polymer have been extensively used as raw materials in AM techniques. Recently, new materials such as glass, ceramic, and composite materials have been added to this group. AM technologies have contributed to a wide range of industrial applications. Every AM production technique has specific properties and performance required by a special application, with the advantage that the desirable properties could be precisely designed through properly selecting the processing type and material compositions. In this chapter, we focus on seven different types of AM processes, and special materials applied in major industrial applications.