A sprung floor is also sometimes referred to as a floating floor. That term, though, more often refers to a floor that insulates against noise or a raised floor with ducts and wires underneath, as in computer facilities.
The top layer of a sprung floor is a performance surface. In dance this may be replaceable to suit different styles; such surfaces are often also called marley floors or dance floors. Here the term floor surface or just surface is used.
A sprung floor excluding the surface is often referred to as the sub-floor, though this may also refer to the concrete or other floor under a sprung floor.
The term speed refers to the traction (kinetic friction) of performance surfaces: fast describes a slippery surface, and slow describes a higher-traction surface, like a gym floor.