3D printing describes a wide array of different technology that all similar but do it in different way. The various types of 3D printer are describes below.

1.   Vat Photopolymerization
Laser-based stereolithography (SLA) and digital light processing (DLP) 3D printing
The first 3D printing process created- vat of liquid that turn solid when it exposed to UV light in selective ways and pulling that print out change it light layer by layer to make sure its create each layer of the object as pulling out. There are couple of different ways to this but they all falls under the same basic idea. There are used by couple of different companies. It allow for super high details models that are absolutely beautiful. However it does has couple of disadvantageous.
1. Only used single type of material.
2. UV curing polymer sometimes it hard to work with and can be a little bit toxic.
3. Material a little bit expensive.

2.  FDM-Fused Deposition Modelling (or Fused filament fabrication-FFF 3D printing)

The mist ambiguities 3D printing available.
Mature technology and many company used it for years.
High end machine quite amazing with it.
Can use a variety of materials and many of them are very cheap in cost.
Some FFF 3D printer can print more than one material.
Overall FFF 3D printer is super cool and

3.  Material Jetting
Head likes inkjet printer turn liquid to solid immediately using UV curing, heat curing and deposited layer by layer.
Few company build it and very expensive.

4.  Binder jetting
Thin layer dusk and binder act as glue.
Can be full colour.
Don’t have to worry of support.
It’s very large -need reservoir and very messy with messy dusk
More expensive technology and few company have control over the pattern.
the layer very high resolution.

5.  Powder bed fusion
The same idea of binder jetting.
Powdery substance and bind it to itself or used laser to melt and harden.
can create part that so strong
High power laser and expensive.
the layer very high resolution.

6.  Direct energy deposition
Kind of new technology- basically is welding in 3D
Filament of metal and melt it and create in 3D.
Very strong part
Imprecise and rough and not high details.
Need to mill the edge to create smooth surface.

7.  Sheet lamination
Laying down a sheet of paper and cut it out with the shape by using cutter and glue it and laying down another piece of paper-cutting out that layer-glue it. Layer by layer building up the object.
Can create full colour print and absolutely beautiful.
Look like a particle board and solid.
Clean and easy to use