Questions using this tag should involve the Bowden extruder - a type of FDM extruder that doesn't have the motor mounted to the printer's XY gantry.

The Bowden extruder is a type of coldend where the filament feeding mechanism consists of a long PTFE sheath containing the filament as a Bowden cable with a frame mounted motor pushing the filament into the hotend, instead of mounting the motor right next the extruder hotend. More details here.