If you want to know more about FDM 3D printing or you want to start messing with FDM 3D printers, you may come to the right place. 

A fused deposition modeling 3D printer (FDM 3D printer) extrudes material through a hot end and deposits those material to the hot plate.  The hot end will follow a path controlled by codes and eventually generate the 3D part the user desires. 

It is a mature technique that can trace back to the early 2010s and it become popular in recent decades as costs for both printers and materials reduce drastically, and the patent of the FDM 3D printer expired around a decade ago. 

(Disclaimer)

I am NOT a professional 3D print worker and all I share on this website can only serve as advice and starting guide for 3D hobbyists.  If you really want to get into this 3D printing working field, please do more research and consult a true professional.