The cover picture of this volume displays one of the most advanced products of he lioseismic research: a view into the deep interior of the sun, revealing its distinctly non-uniform rotation throughout the entire depth of the convection zone. Just over 20 years ago, the first successful helioseismic experiment disclosed an increase of ro tation velocity in the uppermost one dozen megameters below the photosphere. The stunning progress in depth and detail highlighted by the cover diagram (and by others shown in this volume as well) was made possible by considerable advances in instru mentation, by the development of powerful analytical tools and, foremost, by the involvement of new brains of enthusiastic proselytes and newcomers to the field, in creasing nearly exponentially in number every year. New branches of research widened the scope of "uranoseismology", as e. g. time-distance seismology (the promising av enue towards small-scale and short-time variability), atmospheric seismology (a new look at strange phenomena we have all ways seen, but hardly understood), and finally the growing observational assault on hundreds of individual stars which are either manifestly or supposedly oscillating -i. e. asteroseismology. The formation of numer ous solar and stellar observing networks and, ultimately, space missions like SOHO have greatly promoted the potential of this science. This steady progress was accompanied by workshops, colloquia, and symposia in quick succession.

The continuing success of helio- and asteroseismology in studying the internal structure and dynamics of the Sun, and of other single stars, has been highlighted in recent years by many topical meetings. The present Proceedings document the first Seismology symposium ever held in conjunction with an IAU General Assembly. This substantially influenced the layout of the scientific programme and demonstrates the vitality of this field of astronomy. The invited reviews are intended to address an audience that includes many non-specialists. Therefore, this volume is particularly valuable as an introduction to the general concepts of the field, and for conveying the excitement that comes with discussions of the most recent observational and theoretical results. There are two chapters on the many facets of asteroseismology, which also compare solar and stellar achievements. A major focus of the symposium was the new developments resulting from the observations of unprecedented quality obtained from global multi-site networks, and especially from the Solar and Heliospheric Observatory SoHO, currently continuing its observations from the Lagrangian point L1. From the center of the Sun to its outer layers, the reader will learn how modern diagnostic techniques reveal the inextricable links between the complex structure of the interior and atmosphere of our nearest star. The book is recommended for undergraduates, postgraduates, and professionals with a strong interest in modern developments in astrophysics.