Natural immunity refers to the body's inherent ability to defend itself against infections and diseases. This type of immunity develops when the immune system encounters pathogens, such as viruses or bacteria, for the first time. The body recognizes these invaders and produces specific antibodies to fight them off, creating a memory that helps protect against future infections. Unlike artificial immunity, which comes from vaccines, natural immunity is built through exposure to actual pathogens. For example, when a person contracts an illness like chickenpox, their immune system learns to recognize and combat the virus, often providing long-lasting protection against reinfection.