One important
property of traveling waves is their ability to transport energy from one point to
another without moving real objects between these two points. The
energy is transported by the disturbance generated in the medium. For
example, when you provide energy to one end of a string by moving it up
and down, the wave transports the energy you provided to the other end of
the string. This energy can be used at the other end to do work.
The particles of the string move up and down but the particles of the string do not move
from one end of the string to the other. Forces due to the tension in the
string do work to transfer energy from regions with energy to regions with no
energy.