Surveying both theoretical and experimental aspects of chaotic behavior, this book presents chaos as a model for many seemingly random processes in nature. Basic notions from the theory of dynamical systems, bifurcation theory and the properties of chaotic solutions are then described and illustrated by examples. A review of numerical methods used both in studies of mathematical models and in the interpretation of experimental data is also provided. In addition, an extensive survey of experimental observation of chaotic behavior and methods of its analysis are used to stress universal features of the phenomenon.