The idea of signals and systems arises in different disciplines such as science, engineering, economics, politics, and medicine. Typical examples of systems include radio and television, telephone networks, radar systems, computer networks, wireless communication, military surveillance systems, and satellite communication systems. Knowledge of a broad range of signals and systems is of practical value to engineering students because engineers must be familiar with signal and system concepts to analyze some specific signals and systems they will deal with in their professional lives. This book is intended to serve as a textbook for junior-level students in electrical and computer engineering. The main aim of this second edition is to improve the clarity of the first edition and fulfill the same objective as the first, which is to present continuous-time and discrete-time signals and systems to electrical and computer engineering students in a manner that is clearer, more interesting, and easier to understand than other texts.