In this volume, observational data derived from the world's largest solar telescopes are correlated with theoretical discussions in nuclear and atomic physics by contributors representing a wide range of interests in solar research. Focusing both on processes occurring at the interior of the Sun and on complicated features observed at its surface, these chapters offer both basic explanations of solar phenomena and an overview of present controversies. Three areas of research covered in the volume are of particular interest: the pulsating nature of the Sun and how these oscillations facilitate the measurement of temperature, density, and pressure of its interior, thus revealing the depth of the surface convection zone and the composition of central regions; confirmation of the predicted flux of neutrinos via solar oscillation observations, yielding new speculations that they are produced at the solar centre but are converted to unobservable forms in passing through the Sun as they escape; and the interpretation of magnetic surface structures, based on both groundbased and space observations, in terms of chromosphere heating.