The branch of biology which deals with the study of immune system in all organisms is referred to as immunology. It measures and contextualizes the physiological functioning of the immune system in terms of both health and diseases. It also observes the malfunctions of the immune system in immunological disorders such as autoimmune disease, hypersensitivities, immune deficiency and transplant rejection. Immunology studies the physical, chemical and physiological characteristics of the components of the immune system. It is applied in various disciplines of medicine, including organ transplantation, oncology, virology, rheumatology, bacteriology, parasitology, psychiatry and dermatology. This book is a valuable compilation of topics, ranging from the basic to the most complex theories and principles in the field of immunology. It brings forth some of the most innovative concepts and elucidates the unexplored aspects of this field. This book aims to serve as a resource guide for students and experts alike and contribute to the growth of the discipline.