This book is a comprehensive balanced and up-to-date introduction to nuclear physics that describes the experiments made to study nuclear reactions and nuclear structure, and the theories and models that have been developed to understand the properties of nuclei and their interactions. After a historical introduction, there are chapters on nuclear accelerators and detectors, elementary particles, nuclear forces, nuclear reaction theory, nuclear models, nuclear and heavy ion reactions, nuclear astrophysics and nuclear reactors. While primarily aimed at undergraduates it will also serve as a reference for graduate students and professional nuclear physicists.