  Studying exoplanets with their parent stars is crucial to understand their
population, formation and history. We review some of the key questions
regarding their evolution with particular emphasis on giant gaseous exoplanets
orbiting close to solar-type stars. For masses above that of Saturn, transiting
exoplanets have large radii indicative of the presence of a massive
hydrogen-helium envelope. Theoretical models show that this envelope
progressively cools and contracts with a rate of energy loss inversely
proportional to the planetary age. The combined measurement of planetary mass,
radius and a constraint on the (stellar) age enables a global determination of
the amount of heavy elements present in the planet interior. The comparison
with stellar metallicity shows a correlation between the two, indicating that
accretion played a crucial role in the formation of planets. The dynamical
evolution of exoplanets also depends on the properties of the central star. We
show that the lack of massive giant planets and brown dwarfs in close orbit
around G-dwarfs and their presence around F-dwarfs are probably tied to the
different properties of dissipation in the stellar interiors. Both the
evolution and the composition of stars and planets are intimately linked.
