  We review the interior structure and evolution of Jupiter, Saturn, Uranus and
Neptune, and giant exoplanets with particular emphasis on constraining their
global composition. Compared to the first edition of this review, we provide a
new discussion of the atmospheric compositions of the solar system giant
planets, we discuss the discovery of oscillations of Jupiter and Saturn, the
significant improvements in our understanding of the behavior of material at
high pressures and the consequences for interior and evolution models. We place
the giant planets in our Solar System in context with the trends seen for
exoplanets.
