Filament deposition modeling (FDM), also indicated as fused filament fabrication (FFF) is an additive manufacturing process, by which the material is melted and extruded through a nozzle to 3D print a cross-section of an object moving layer by layer.
There are many different materials for this type of printing process, the most common are: ABS, PLA, Polycarbonate.
Very simple and low-cost machines
Good mechanical strength of the pieces
Poor surface finish
Requires support structures