The wheel rebound (low, medium or high) indicates how much elasticity, spring or bounce energy is in a wheel. Another way to look at rebound is as how much memory a wheel has - a wheel with higher rebound will return to its original shape after the compression of a stroke much quicker.
Rebound can be tested by dropping a wheel to see how far up it will bounce back. A wheel with high rebound will work with a skater’s stroking effort by pushing back quickly, but wheels with low rebound may absorb a skater’s effort. Wheels with high rebound will also roll longer from the same skating stroke than a low rebound wheel. Rebound is designed into the whole wheel, including the polyurethane and the hub or core assembly, since the wheel hub design can have an effect on the flexibility in a wheel. High rebound wheels have many good qualities, but they may cost more and have a shorter skating life.