What is the meaning of immunity?

Immunity refers to the body's ability to resist or fight off infections and diseases caused by pathogens such as bacteria, viruses, and fungi. It encompasses a complex network of cells and processes that work together to identify and neutralize harmful invaders. When the body is exposed to a pathogen, the immune system generates a response that can include the production of antibodies, activation of immune cells, and memory cells that help future responses against the same pathogen.

This functional capability is crucial for maintaining overall health and preventing illnesses, explaining why it is the most fitting definition among the choices provided. The other options relate to different concepts: allergic reactions involve the immune system responding to harmless substances, the ability to heal quickly refers to physical recovery processes, and the acquisition of new skills pertains to learning and personal development. Understanding immunity is essential for anyone studying health or related fields, as it lays the foundation for preventing and treating infections effectively.