The scientific study of the body's defenses against disease is known as immunology. It focuses on the immune system, which includes various cells, tissues, and organs that protect the body from pathogens like bacteria, viruses, and parasites. Immunologists investigate how the immune response is activated, how it functions, and ways to enhance or modify it. This field also explores vaccination, autoimmune disorders, and allergies, contributing to advancements in medical therapies and public health initiatives aimed at disease prevention.