There are three basic ways in which heat is transferred. In fluids, heat
is often transferred by convection, in which the motion of the fluid
itself carries heat from one place to another. Another way to transfer
heat is by conduction, which does not involve any motion of a substance,
but rather is a transfer of energy within a substance (or between
substances in contact). The third way to transfer energy is by
radiation, which involves absorbing or giving off electromagnetic waves.
