It is very enticing to have a strong immune system. An immune system helps the body to thwart infection. The body has two types of immune systems: natural and acquired. Natural immunity allows our body to thwart foreign particles with physical barriers such as skin and white blood cells. Acquired or adaptive immunity allows our body to recognize and fight any infection by utilizing specialized antibodies. Although scientists are still trying to understand the intricacy of the immune system, in the simplest terms, it relies on distinguishing our body from foreign bodies.
There can be a temporary loss of immunity due to infections, surgery, malnutrition, stress, etc. We can boost our immune system with a proper diet and regular exercise—that is, by adopting a healthier lifestyle.
Hope this helps.