3D printing or additive manufacturing is a process of making three
dimensional solid objects from a digital file. The creation of a 3D
printed object is achieved by using additive processes. In an
additive process an object is created by laying down successive
layers of material until the entire object is created. Each of
these layers can be seen as a thinly sliced horizontal
cross-srction of the eventual object.
Not all 3D printers use the same technology. There are several ways
to print and all those available ones are additive, differing
mainly in the way layers are build to create the final object.
Some methods use melting or softening material to produce the
layers. Selective laser sintering (SLS) and fused deposition
modeling (FDM) are the most common technologies that use this way
of printing. Another method of printing is when we talk about
curing a photo-reactive resin with a UV laser or another similar
power source one layer at a time. The most common technology using
this method is called stereolithography (SLA).