This monograph provides an accessible introduction to the theory, and the large-scale simulation methods currently used in radiation hydrodynamics, the study of the dynamics of matter interacting with radiation, when the radiation is strong enough to have a profound effect on the matter. Radiation hydrodynamics applies to normal stars, exploding stars or stars with violent winds, active galaxies, and on Earth wherever matter is very hot. The volume is a valuable text for research scientists and graduate students in physics and astrophysics.