A machine that creates a product one layer at a time (the additive fabrication method). Used mostly for quickly creating prototypes and molds, 3D printers are also used to build final parts. Available for myriad industrial uses as well as for the hobbyist, a variety of different technologies are used to form the layers.

Initially, 3D printers referred only to the relatively small, inexpensive office-based machines that jet a wax, photopolymer or binder. Increasingly, the term refers to any machine that uses a method of additive fabrication either in the office or shop floor.