Skin is the outermost covering of mammalian body. It has three layers: epidermis, dermis and subcutis. The outermost layer of our skin is called the epidermis. This thin, tough layer consists of mostly keratinocyte cells. These cells originate from the basal layer of the epidermis and migrate to the outer layers and replace older outermost cells (which are removed by shedding). The epidermis protects us from most injuries, is waterproof and may be thicker in regions requiring extra protection (such as palm, etc.). The flexibility and strength of the skin can be attributed to the dermis layer. This layer consists of nerve cells, sweat glands and roots (follicles) of hairs. The subcutis consists of fat layers and fibrous tissues that protect our body from external temperature (hot and cold) and acts as a padding.
Hope this helps.