Re: What's the difference
From the point of the view of the proposed legislation there is no difference.
What most people think of as drones are more correctly described as MultiRotors but the proposed legislation defines a drone as any Unnanned Airbourne Vehicle (UAV). That means it impacts model planes (including free flight models), model helicopters and the quadcopters people tend to think of when you say drone.
As there’s no defined weight limit yet (250g is often mentioned but as there’s no laws it’s still an unknown) then technically even a paper plane will fall under the UAV description.