Addtive manufacturing or 3D printing is defined as the process of joining materials to make objects from 3D model data, usually layer unpon layer, as opposed to subtractive manufacturing methodologies.
IAvailable materials & technologies in additive manufacturing:
Polymer: Material extrusion(FDM, FFF), Material Jetting(Polyjet, MJF), , Material sintering(SLS), Photopolymerization(SLA, LCD, DLP)
Metal: Powder Bed Fusion, Directed Energy Deposition, Material Extrusion, Binder Jetting, Material Jetting, Sheet Lamination.
As 3D Printing can create objects directly from the digital model, it more and more used today to make proofs, Prototypes, low-volume production end-use parts.