Presenting the fundamentals of modern ideas on the structure of atomic nuclei, as well as the most recent results. Different models of the nucleus are examined in detail and their interrelations are also discussed. Among the subjects dealt with are the fundamentals of quantum chromodynamics, quark models of hadrons and their classification, continuous groups, strong interactions and a detailed analysis of the deuteron and three nucleon nuclei, and many-quark systems. With the exception of Chapter 7, all chapters are supplemented by a problem section, and a detailed bibliography has been added for further study. This volume should be of interest to research workers in the field of nuclear physics, particle physics and nuclear engineering, as well as to postgraduate students of physics and engineering. It can also be used as a supplementary textbook.