  Almost 100 years ago Sir Arthur Eddington noted that the interiors of stars
were inaccessible to observations. The advent of helio- and asteroseismology
has completely changed this assessment. Helioseismology has provided very
detailed information about the interior structure and dynamics of the Sun,
highlighting remaining issues in our understanding of the solar interior. In
the last decade extensive observations of stellar oscillations, in particular
from space photometry, have provided very detailed information about the global
and internal properties of stars. Here I provide an overview of these
developments, including the remarkable insight that has been obtained on the
properties of evolved stars.
