Basic purpose of this lecture is to present on the Immune System. Here briefly present on cells of the Immune System. The immune system is a system of many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism’s own healthy tissue. Finally focus on Different Immunoglobulins, Active and Passive Immunity and Vaccination.