This is a presentation of different types of immune responses in human body. There are two types of immune systems i.e., non specific and specific or adaptive immune system. Again, non specific immune system is sub- divided into barriers. It is the first line of defense. The second line of defense is the inflammatory response. They are phagocytes. These are all products of white blood cells. It is also called as leukocytes. Lymphocytes are another type of white blood cells which are carriers of specific immunity. Lymphocytes are again sub-divided into B-lymphocytes and T- lymphocytes. The B- lymphocytes are produced in bone marrow where as T-lymphocytes are also produced in bone marrow but they mature in Thymus.