The term “signals and systems” are used broadly in diverse fields that have applications in a broad class of problems including communications, VLSI circuit design, acoustics, aeronautics, biomedical engineering, speech processing, radar system design, pattern recognition and multimedia technology. The subject is a core text for students of circuit. An in-depth knowledge in this subject is mandatory to understand various subjects such as digital signal processing, digital image processing, speech signal processing, VLSI signal processing and radar signal processing. This book focuses on the concepts of signals, different types of signals, an introduction to systems theory, system analysis, etc. Also, this book looks at the way that signals interact with physical systems.