Immunology is a domain of biology that is concerned with the study of immune systems in different organisms. It is involved in measuring and contextualizing the physiological functioning of the immune system in both healthy and diseased state. It also studies the malfunctions of the immune system during immunological disorders as well as the chemical, physical and physiological characteristics of the constituents of immune system. There are various fields of immunology such as classical immunology, clinical immunology, developmental immunology, diagnostic immunology, reproductive immunology and theoretical immunology. It plays a vital role in diverse fields of medicine such as organ transplantation, oncology, rheumatology, bacteriology, parasitology, virology, psychiatry and dermatology. This textbook provides comprehensive insights into the field of immunology. Some of the diverse topics covered herein address the varied branches that fall under this category. Those in search of information to further their knowledge will be greatly assisted by this book.