Signals and Systems is a comprehensive text tailored to meet the undergraduate students of electrical or electronics engineering programmes offered by various universities and institutes. This book acts as a foundation and prepares the students for advanced courses in control systems, circuit theory, communication engineering, and other similar fields. This book is designed to teach students how to apply mathematical tools in a nontrivial sense to solve engineering problems. It will also help them appreciate the usefulness of these tools by relating the physical phenomena to their mathematical depiction. This book explores the concepts and characteristics of both continuous-time and discrete-time signals and systems.