1. Innate Immunity: This is the body's first line of defense against pathogens. It's non-specific, meaning it acts against a wide range of invaders, and it's present from birth. Some examples include:

* Physical barriers: Skin, mucous membranes, cilia.

* Chemical barriers: Stomach acid, enzymes in saliva and tears.

* Cellular components: Phagocytes (neutrophils, macrophages), natural killer cells.

* Inflammation: Redness, swelling, heat, pain.

2. Adaptive Immunity: This is a more specific and targeted defense system that develops over time. It involves the recognition of specific pathogens and the development of a memory response to them. This type of immunity is acquired through exposure to pathogens or vaccines. It can be further divided into:

* Humoral immunity: Involves B cells producing antibodies that target specific antigens.

* Cell-mediated immunity: Involves T cells that directly attack infected cells or destroy pathogens.