Waypoints polyline vs arc

Does anyone know the difference between polyline and arc in waypoints 2.0 (other than no automatic camera action in arc)?

The polyline route type will make the aircraft fly a straight line from waypoint to waypoint. Arc will make the aircraft fly a smooth curved path as it arrives and leaves a waypoint.

See more details in #11 here:
HOW TO: Fly automated missions with Waypoints 2.0 in DJI GO (The Complete Guide)

Thanks, I have been looking for something like this that explains all the details.