This textbook on Signals and Systems is for second-year degree level students. The purpose of writing this book is to provide the reader with a precise, practical and up-to-date exposition of signals and systems. Accordingly, this book contains a wealth of material that trains a student to face the challenges posed by the growing trends in communication, control and signal processing areas. The book is suitable for practicing engineers as well, considering the fact that many engineers from the industry may wish to change their career by adapting to the fields in demand, such as digital communication and signal processing.