The purpose of this book is to review the current state of this quickly developing field. Up until now, there has been no concise review available of the rather diverse aspects of this field. This book gives a basic introduction to the concepts behind Bloch oscillations. It describes how the physics of high field transport has been investigated through a broad range of experimental techniques such as interband and intraband optical spectroscopy and transport experiments. Possible applications and further trends are also discussed.