Elasticity is a term in physics used to describe the ability of an object to return to its original form after being distorted. Examples of objects with elasticity are piano wires, springs and rubber bands.
The more an object is able to return to its original shape, the more elasticity it is said to have. A rubber band can be easily stretched and will return to a close approximation of its original shape. A piano wire, while not as easy to stretch as a rubber band, will return to its exact original shape. This precision is needed to keep the piano from becoming out of tune. As a result, the piano wire has more elasticity than the rubber band.