This book reviews the physiological and therapeutic applications of extracellular vesicles (EV) of different cell types. The initial chapter of the book focuses on their evolution, physiological functions, inter- and intra-cellular communication, and their strategic applications in defining different health disorders including aging, pathogenicity, toxicity, and drug delivery. The chapter also provides an overview of recent technologies for EV isolation, analysis, and quantification. The chapter also examines the role of EVs in viral and bacterial pathogenesis and discusses the emerging potential of EVs as diagnostic and therapeutic tools. It also discusses the emerging role of EVs including endosome-derived exosomes and fragments of the cellular plasma membrane in intercellular communication by transporting messenger RNA, microRNA (miRNA), and proteins. The book further explores the potential of membrane vesicles in the prevention, diagnosis, and treatment of inflammatory diseases, metabolic disorders, cardiovascular diseases, and neurodegenerative disorders. This book address researchers, clinicians, and doctoral and graduate students working in cellular molecular biology, cancer biology, infectious diseases, molecular medicine, biomedicine, neurobiology, microbiology, and translational medicine.