When it comes to hotends and extruders you will often hear the terms Direct and Bowden systems mentioned.
A Direct drive setup refers to when the extruder and motor are mounted on top of the hotend, this allows a reduced filament path for a greater control on the filament due to the faster response time and reduced friction.
A Bowden setup refers to when the extruder and motor are mounted elsewhere on the frame and feeds the filament to the hotend using a Bowden (PTFE) Tube, this allows for reduced weight and inertia on the tool head meaning faster and more accurate prints can be achieved with fewer print artefacts.