  Relativistic hydrodynamics is essential to our current understanding of
nucleus-nucleus collisions at ultrarelativistic energies (current experiments
at the Relativistic Heavy Ion Collider, forthcoming experiments at the CERN
Large Hadron Collider). This is an introduction to relativistic hydrodynamics
for graduate students. It includes a detailed derivation of the equations, and
a description of the hydrodynamical evolution of a heavy-ion collisions. Some
knowledge of thermodynamics and special relativity is assumed.
