The epidermis is the most superficial layer of the skin, and is largely formed by layers of keratinocytes undergoing terminal maturation. This involves increased keratin production and migration toward the external surface, a process termed cornification. What is the epidermis layer of skin? Your skin has three main layers, and the epidermis (ep-uh-derm-us) is the outermost layer in your body. The other two layers of skin are the dermis and hypodermis. The epidermis is the thinnest layer of skin, but it’s responsible for protecting you from the outside world, and it’s composed of five layers of its own. The epidermis is the outermost covering of the skin. Read the article to learn more about its structure and function. The epidermis is the outermost layer of skin that does more than just shield the body from mechanical injury. Learn more about this organ system.