Wave
Push / sweet spot
The clean section of the wave that propels the rider forward without the rope; finding it is what lets you ride hands-free.
The push is the wave's propulsive force, the energy that carries a wakesurfer along after the rope is dropped. The sweet spot is the position in the wave where that push is strongest, the clean part of the wave just ahead of the white water with no foam underfoot. When a rider settles into the sweet spot the tow rope goes slack, the signal that it's time to let go.
Staying in the push is an active job: riders pump and adjust position constantly to remain in the zone where the wave does the work for them.