Immunities refer to the body's ability to resist or fight off infections and diseases. This protection is primarily provided by the immune system, which includes various cells, tissues, and organs that work together to identify and eliminate harmful pathogens like bacteria and viruses. There are two main types of immunity: innate immunity, which is the body's first line of defense and is present from birth, and adaptive immunity, which develops over time as the body encounters specific pathogens. Vaccines can help enhance adaptive immunity by training the body to recognize and respond to particular threats more effectively.