A trampoline is a device consisting of a piece of taut, strong fabric stretched over a steel frame using many coiled springs. People bounce on trampolines for recreational and competitive purposes.
The fabric on which users bounce (commonly known as the 'bounce mat' or 'trampoline bed') is not elastic in itself; the elasticity is provided by the springs that connect it to the frame, which store potential energy.
Read more about Trampoline: Safety, Mini-trampolines, Educational Use