Astrobiology refers to the study of the origin, evolution, distribution, and future of life in the universe. This encompasses extraterrestrial life and life on Earth. Astrobiology is an interdisciplinary field that is gaining a rapidly growing interest among both the general public and the astronomical research community. This e-book explains the detection and evolution of exoplanets and discusses the question of habitability on such objects. Chapters in this text include cited references enabling the reader to acquire more information on specific aspects of astrobiology. It is also a suitable textbook for introductory taught courses in universities and colleges on the subject.