This book is the latest in the recently established `IET Book Series on Advances in Biometrics'. The history of this Series dates back to the publication by the IET a few years ago of the book `Age Factors in Biometric Processing', which provided the impetus and set the pattern for an on-going Series of books, each of which focuses on a key topic in biometrics. Each individual volume will bring together different perspectives and state-of-the-art thinking in its topic area, shedding light on academic research, industrial practice, societal concerns and so on and providing new insights to illuminate and integrate both specific and broader issues of relevance and importance. This book addresses this important area, but rather than focusing on any specific hand-based modality, it draws together a number of important topics which collectively offer a view of the wide range of information which the hand provides, thereby capturing and surveying the diversity of hand-based biometrics. This breadth of coverage sets this book apart from others which address individual handbased modalities but also allows the inclusion of informative contributions on the physiology of the hand, providing insights into the very foundations of hand-based biometrics. This ground-breaking approach makes the book a particularly welcome addition to the Series.