The network of biological processes which protect an organism from different types of diseases is termed as the immune system. It deals with a wide variety of pathogens ranging from parasites to viruses, as well as potentially infectious objects like wood splinters. The branch of biology which focuses on the immune systems of various organisms is known as immunology. It makes use of immunology charts to contextualize the physiological functions of immune system, and detect different types of immunological disorders. Inflammatory disease, cancer, hypersensitivity, autoimmune disease, and immune deficiency are some of the common examples of disorders related to the immune system. The discipline of immunology can be further classified into developmental immunology, classical immunology, reproductive immunology, diagnostic immunology and theoretical immunology. The book aims to shed light on some of the unexplored aspects of the functions and disorders of the immune system, and the recent researches in this field. It strives to provide a fair idea about this discipline and to help develop a better understanding of the latest advances within this field. This book will help the readers in keeping pace with the rapid changes in this field.