The skin can be divided into the epidermis, dermis and subcutaneous fat layer, of which the epidermis includes five different structures, namely, stratum corneum, stratum pellucidum, stratum granulosum, stratum spinosum, and stratum basale, and different epidermal layers, the specific functions are different. 1. The stratum corneum: it protects the skin, resists friction, prevents the penetration of tissue fluids from the body, and prevents the entry of chemicals or bacteria from outside the body. 2. Transparent layer, which is mainly distributed in the palm of the hand as well as the foot area, has the function of preventing water loss. 3. Granular layer: It can prevent the intrusion of abnormal objects from outside to a certain extent, and filter ultraviolet rays appropriately. 4. Epidermis: a thicker layer of epidermal tissue that stores lymphatic fluid and provides nutrients for cell growth. 5. Basal layer: It is mainly located in the deepest part of the epidermis and has the function of dividing and replicating. If the epidermis is broken, then it will promote the growth and repair of the cells in the basal layer, so that the skin will gradually return to normal. In normal times, it is important to pay attention to the protection of the epidermis, pay attention to personal hygiene, try not to let it be unnecessarily hurt, so as not to hinder the normal function of the skin.