FDM printers

FDM (also called FFF) printing technology is the most popular of all. It uses a plastic filament as an input that the printer melts and deposits in a controlled manner to create 3D parts. It is capable of using a wide variety of different plastics depending on the use that will be given to the printed part. The mechanism and its use are simple. This, added to the low cost of equipment and supplies, made it the most widely used technology. FDM 3D printers are based on 3 main elements:

A heated bed or build surface on which the part is built

A spool or roll of filament, which is the material of construction for the part (such as ink from a paper printer)

An extrusion head, also called a hotend

The filament is pulled by the extrusion head and is melted at a controlled temperature to be precisely deposited layer by layer on the hot bed.
Among the compatible materials for FDM printers we can mention PETG, ABS, PLA,Nylon, HIPS And a long etcetera. Printing areas range from 200 x 200 to 1m x 1m. They are used for the manufacture of prototypes, functional parts, figures, etc. 
Its dimensional accuracy and print quality are very good, but not as good as SLS or resin systems.
Among its main advantages we can mention its low cost of acquisition and operation, ease of use and variety of available materials.
It is an excellent tool for companies, educational establishments, professionals and hobbyists.