With the discovery of high-temperature superconductors, research into polarons and bipolarons has attracted much attention. This book is the first standard reference to give a comprehensive view of the polaron and bipolaron theory of high-temperature superconductivity, one of the most significant discoveries in physics in the past decade. Scientists have also observed polarons and bipolarons in magnetic semiconductors and transition metal oxides. The thorough investigation of these nonsuperconducting materials has contributed greatly to our basic understanding of the physical properties of both polarons and bipolarons. This book contains a series of authoritative articles on the most advanced research on polarons and bipolarons in high-temperature superconductors and related materials. This book will be of great interest to researchers in condensed matter physics, and especially those working in the field of superconductivity.