Stereolithography belongs to the more general group of Direct Printing (or DP), All direct printing techniques produce approximate models, defined as 2.5D i.e., obtained by joining a very dense series of discrete sections, called layers.
Stereolithography is a rapid prototyping technique that allows the construction of parts by selective addition of material in liquid form in a tank. The material is processed by an ultraviolet laser, which goes to reinforce it and forms the object.
Specifically, stereolithography has a very refined layer tickness that allows the construction of models of high detail. It can build rigid parts, both opaque and transparent, and equipped with important mechanical characteristic, especially if ceramic-enriched material (ceramic 3D printing) is adopted.