The
innate immune system, also known as the
nonspecific immune system or in-born immunity system, is an important subsystem of the overall
immune system that comprises the cells and mechanisms that defend the host from infection by other organisms. The cells of the innate system recognize and respond to
pathogens in a generic way, but, unlike the
adaptive immune system, it does not confer long-lasting or protective immunity to the host. Innate immune systems provide immediate defense against infection, and are found in all classes of
plant and
animal life.