The modern piano as we know it is over 300 years old. Having it around for so long sometimes causes us to forget just how incredible an instrument it is. Knowledge of the parts and materials that make the piano what it is, and the appreciation of the instruments before it that led to its creation gives the pianist not only a better relationship with the instrument, but allows the pianist to fully understand the fundamental components of the instrument and then take advantage of each of them to use the instrument to the best of its abilities.
This link gives substantial information on the instrument and its predecessors. All credit to Nicholas Giordano.