There are several different methods used in 3d printing, aka Additive Manufacturing. This list is not exhaustive.
additive manufacturing (AM) process in which a liquid binder is selectively applied to thin layers of powder. Color is an optional additive in some cases.
Continuous Liquid Interface Production, a proprietary light-directed AM process developed by Carbon3d.
Computer Numerical Control, the application of manufacturing tools (e.g. lathe, engraver) that are guided by software.
an FDM machine in which three motorized print arms support and guide the extruder above a round printbed.
Digital Light Processing, a vat photopolymerization technique in which a photo-reactive polymer is hardened by an image projected onto it by a digital projector screen.
Direct Laser Writing, a microscopic method of AM which uses a highly focused laser to create a volumetric form in a photoactive liquid. Find out how DLW technology was used to create the smallest human figure.
a metal SLS technique, Direct Metal Laser Sintering is a powderbed process that uses a laser to bind metal particles together. It is different from another powder metal AM process, SLM (selective laser melting), which fully melts the particles together. An advantage of DMLS is that it is available with more materials. To see more info on metal AM, visit this article here.
electron beam melting, an AM process in which metal powders are welded by an electron beam. To see more info on metal AM, visit this article at element.
Fused Deposition Modeling (FDM), sometimes called Fused Filament Fabrication (FFF), is the dominant AM technology of consumer/desktop 3d printers. A software-controlled extruder/hot-end deposits molten thermoplastic in layers. The layers consist of images produced by slicing software, creating an object, or model, in a series of cross-sections.
Gel Deposition Printing is a “cold” process that prints with a UV-cured photopolymer gel.
workflow that incorporates additive manufacturing and subtractive machining processes (e.g. milling for surface finish) on one machine.
Multi-Jet Fabrication, a powderbed AM process in which printheads dispense a liquid binder to nylon powder, which is then subjected to infrared light to firmly fuse together.
Screw Extrusion Additive Manufacturing, a system that extrudes raw (pellet?) plastic over a 6-axis build platform. Additionally, the swivel-action of the platform allows for depositing on existing components.
StereoLithography Apparatus is credited as the original technology in the family of AM processes, followed shortly after by SLS and FDM machines. SLA printers are among consumer desktop models, are noted for higher resolution than their FDM counterparts, and use the solidification of liquid photopolymer resin.
Selective Laser Melting, a powderbed AM process that heats metal particles together for a dense build. It differs from DMLS, which heats particles together to bond at the molecular level without fully melting them. For more info on metal AM, visit here.
Selective Laser Sintering, a powderbed fusion AM process. It is a layered technique in which lasers are used to fuse together nylon powder.
In Wire Arc Additive Manufacturing, a metal structure can be welded in 3d space (as opposed to most AM processes built in a succession of 2d layers) via robotic arm.