This book describes examples and applications of synchronization, and gives the problem a working mathematical formulation. It presents the basic principles and results, as well as some of the open problems. It is intended for a wide range of specialists who may encounter nonlinear vibrations problems: mathematicians, engineers, physicists, chemists, and biologists, as well as students in these fields. Topics covered include: General Formulation of the Problems and Characteristics of the Basic Mathematical Apparatus for the Synchronization Theory of Dynamic Systems, Synchronization of Technological and Natural Objects, and Mathematical Apparatus and Principal Results of the General Theory of Synchronization of Weakly Coupled Dynamic Objects.