Immunity is an evolutionarily conserved defense strategy, inherent in both plants and animals, for disease tolerance. It confers the host protection against viral, bacterial, protozoan, and fungal infections. Immune system cells emanate from the bone marrow and subsequently move to the peripheral tissues to defend them. They travel through the bloodstream and the lymphatic system, which is a specialized system of channels. They do so after maturation in the bone marrow These pluripotent hematopoietic stem cells give birth to all types of blood cells, earning them the name pluripotent hematopoietic stem cells. The monocyte, neutrophil, and natural killer (NK) compartments represent the initial line of defense for innate immunological responses among immune cells Adaptive immune system or (behavioral immune response); The adaptive immune system, also known as the acquired immune system, is a part of the immune system that comprises of specialized, systemic cells and processes that kill infections by inhibiting their proliferation. Innate and adaptive immune systems are separated into two categories, each with its own role. Innate immune system or cell-mediated immune response. Adaptive immune system or behavioral immune response. Innate immune system or (cell-mediated immune response); Anti-infection systems in the body's immune response can be engaged swiftly if a pathogen attacks.