Offers authoritative overviews of topics related to the definition, computation and application of molecular similarity and emphasizes current research trends with molecular similarity as the unifying concept. Introduces and defines the concept of molecular similarity and explains how it can be used to explore the data containing 2-D and 3-D chemical information. Addresses the basic problem of relating chemical structures to their associated chemical and biological properties. Final chapters illustrate the use of similarity arguments in the study of chemical reaction pathways and present theoretical approaches to the concept of molecular similarity.