The immune system plays a critical role in overall health by defending against pathogens and disease. Its primary function is to identify and eliminate foreign invaders, such as bacteria, viruses, and parasites. A well-functioning immune system helps prevent infections and reduces the risk of chronic diseases. Moreover, it is influenced by factors like nutrition, exercise, and sleep, which can enhance or weaken its performance. The system comprises various components, including white blood cells, antibodies, and the lymphatic system, working collaboratively to maintain the body's integrity.