This book contains selected papers on difference equations presented at a summer 2001 conference. It covers recent progress in topics ranging from the classical to the contemporary and from theory to applications. Contributions are organized into sections on discrete dynamical systems, dynamic equations of time scales, and miscellaneous difference equations. The collection also includes a lecture on difference equations and boundary value problems, and two discussions on the discrete nature of physical laws and real analysis as a degenerate case of discrete analysis. The book will be valuable for researchers and students working in discrete mathematics, differential equations, and nonlinearity.