Skin

of three layers: epidermis, dermis and hypodermis.
Epidermis is an outer

layer of the skin. It consists of dead cells and protects the body from bacteria and viruses. It keeps water inside the body.
Under the epidermis, there is a layer called dermis. It has receptors, which feel the pain, temperature, pressure. Also dermis has sweat glands and sebaceous gland.
Sweat glands produce sweat.
Sebaceous glands produce oil. Dermis has blood and lymph vessels. They transport nutrients into the skin.

of fat cells. They store energy. Also, fat cells keep

heat inside the body.
Skin protects other tissues from damage. Also, skin excretes excess water and salt by sweat.
Skin is the largest organ in the body. Skin occupies approximately 1.73 square meters to cover our body

a protein produced by skin. When you go out in

the sun, your body makes more melanin to protect you from the sun rays, making your skin darker.
Some people lack melanin. It is a genetic disorder called albinism.