The three layers of the skin are : # Epidermis, which provides waterproofing and serves as a barrier to infection, # Dermis, which supports and anchors the skin, # Hypodermis (subcutaneous adipose tissue layer).
Mammalian skin is composed of three primary layers: the epidermis, which provides waterproofing and serves as a barrier to infection; the dermis, which serves as a location for the appendages of skin; and the hypodermis (subcutaneous adipose layer).
No, it is the most serious of the three degrees, affecting all layers of the skin. Some lists include a "fourth degree burn" (destruction of skin and underlying tissues, muscles, or organs) but this goes beyond the injuries defined by the three layers of the skin.
The skin layers tend to be the same once you get to the taxonomic classification of Order. For instance, birds all tend to have the same skin layers, although these are different from the skin layers of mammals and invertebrates have different layers as well.