FDM-Fused deposition modeling (FDM), also known as fused filament fabrication (FFF).

FDM 3D Printers create models and prototype parts directly from digital data, quickly, easily and locally, for concept verification, design validation and functional testing. 

FDM 3D printers work by extruding thermoplastic filaments, such as ABS (Acrylonitrile Butadiene Styrene), PLA (Polylactic Acid), through a heated nozzle, melting the material and applying the plastic layer by layer to a build platform. Each layer is laid down one at a time until the part is complete.