The primary role of the lymphatic system is to maintain fluid balance and support the immune system. It transports lymph, a fluid containing infection-fighting white blood cells, throughout the body. By filtering lymph through lymph nodes, the system captures pathogens and foreign materials, promoting immune responses. The lymphatic system also absorbs and transports dietary fats from the digestive system. Thus, it plays a crucial role in overall health, combating infections, and ensuring proper fluid distribution in tissues.