This book is a product of a month-long school on mirror symmetry in mathematics and physics organized by the Clay Mathematics Institute and held at Pine Manor College in Massachusetts during the spring of 2000. After sections dealing with mathematical and physical preliminaries, physical and mathematical proofs are presented and considered. A final section considers advanced topics such as topological strings at higher genera and the notion of holomorphic anomaly. Annotation (c) Book News, Inc., Portland, OR (booknews.com)