Innate immunity is the body’s non-specific, first-line defense system present from birth, providing rapid, general protection against any foreign invader by using physical barriers (skin, mucous membranes), chemical secretions (acid, tears, saliva), and immediate cellular responses (like macrophages and neutrophils) to prevent infection and control pathogens quickly, though without lasting memory, unlike the adaptive immune system. Key Features Present at Birth: It’s your natural, inherited immu