FFF (Fused Filament Fabrication) is an 'additive' 3D printing process where a thermoplastic filament  or thread is heated and then printed in layers to produce a three dimensional object.

Objects are first created in CAD software then convert to a file (.STL format) that is readable by a 3D printer.

The printer uses two types of material, scaffold/support and model material. The former is discarded after printing to leave a prefect formed object

During printing a filament or thread of plastic material is fed through a extrusion nozzle that heats the plastic that is then deposited on a build table layer by layer. The printer and build table moves horizontally and vertically (X, Y Z coordinates) determined by the computer software to create a 3D object.