Red giant stars can be used to probe both stellar physics and the star formation history in our Galaxy. This book will present material in a way which is both pedagogical (using dimensional arguments, supported by results from numerical calculations) and forward-looking, stressing how one can address longstanding open questions in stellar evolution using combined asteroseismic, astrometric and spectroscopic constraints. In the current literature, asteroseismology and stellar evolution seldom appear in the same book. Linking asteroseismology and stellar evolution together is a novel approach which will aid the identification of key scientific questions that can be addressed using this technique, together with its limitations.