This volume is designed as a textbook for a graduate or advanced undergraduate course in SETI, exploring the history, theory, and methods of the field. It provides a history and description of modern methods in the major types of SETI (including searches for radio, laser, solar system, and artifact technosignatures) theoretical concepts in SETI (including the Drake equation, Kardaschev scale, and Fermi Paradox), different philosophical approaches to SETI (including game theory, Messaging Extraterrestrial Intelligence (METI), and anthropocentrism), and social aspects of the field (including postdetection protocols and ethical considerations).