Immunity is simply the way our body reacts when any outsider which tries to enter our body. It performs a meticulous security check and kills the harmful outsider with various strategies. Though the process seems simple to us Immunity is or rather the immune system is not a single entity. It comprises of the army of many elements like leukocytes, T cells, B cells, and antibodies, etc. This intelligent system is always on toes and communicates throughout the body to keep a check on all sorts of invaders. Even the minutest of the attacks are monitored and taken care of. All because of the intelligently designed intricate mechanisms. It is important to note that the number and condition of these cells determine the health of our immunity.