FDM 3D printing is an additive manufacturing method which consists of extruding heated material through a nozzle in order to create 3D objects.

The objects are printed one layer at a time, as the layers are extruded they cool which causes them to 'fuse' together.

SLA 3D printing consists of curing liquid resin layer by layer by using UV lasers. Each layer is exposed to the UV lasers for a set amount of time which is enough to partially cure the resin.