Define immunity?

Immunity refers to the ability of an organism to resist or defend against harmful pathogens, such as bacteria, viruses, or parasites. It is a complex system that involves various cells, tissues, and organs working together to recognize and eliminate foreign substances or infectious agents. Immunity can be acquired naturally through exposure to infections or artificially through vaccination. It can also be classified into innate immunity, which is present at birth and provides immediate defense, and adaptive immunity, which develops over time and provides a specific response to particular pathogens.