The immune system is a collection of cells, proteins, and signaling molecules that protect your body against aggression from the outside environment. We sometimes use the terms 'defenses' or 'immunological system' to refer to this inner guardian.
In reality, reaching a perfect understanding of our immune system is a feat that only genetics specialists and immunologists are capable of.
A series of complex stimuli regulate our defenses, determining the location, intensity, and duration of the immune response.
That being said, getting to know our immune system a bit better can help us understand the mechanisms that strengthen or weaken it to stay as healthy as possible. In fact, we can divide this system into two primary forms of immunity (1):
Innate immunity: This primitive system relies on natural barriers (skin, mucus, gastric acids, and sweat, among others) and specific cells (such as macrophages) that destroy microorganisms through stereotyped mechanisms (which do not change depending on the germ).
Adaptive immunity: Also referred to as acquired immune system, it can recognize and respond to a specific microorganism, creating antibodies that facilitate its destruction. The memory of this type of immunity means that its response will be faster the next time you are infected by the same germ.