The role of the immune system is to protect the body from pathogens such as bacteria, viruses, fungi, and parasites. It employs various cells, tissues, and organs, including white blood cells, antibodies, and the lymphatic system, to detect and eliminate foreign invaders. The immune system distinguishes between self and non-self entities, mounting responses that can be immediate or involve long-term immunity. A well-functioning immune system is essential for maintaining health, preventing infections, and enabling the body to recover from diseases.