This book is the second edition of a text designed for undergraduate courses in signals and systems. The book develops the method of analysis for continuous-time signals and systems in parallel with the method of analysis for discrete-time signals and systems. This approach highlights the similarities and differences, and features introductory treatments of the application of these basic methods in areas such as filtering, communication, sampling, discrete-time processing of continuous-times signals, and feedback. Relatively self-contained, the text assumes no prior experience with system analysis, convolution, Fourier analysis, or Laplace and z-transforms. A companion book, "Computer Explorations in Signals and Systems Using MATLAB" (ISBN 0-13-732868-0), contains MATLAB exercises for each topic in this text.