Skin is the largest organ in the human body. The skin of an average male weighs 5 kg and of a female weighs around 3 kg.
Skin has 3 layers. Outer Epidermis is made of 5 layers of cells arranged on top of each other in a brick-wall kind of fashion. These cells, called as keratinocytes, are shed off continuously. In a year approximately 4 kilos of skin cells are shed off.
The middle layer called as Dermis is the thickest part of the skin. This consits of appendages such as hair, sweat and sebaceous glands. All of these is embedded in a bed of collagen and elastic tissue which gives strength, elasticity and structure to the skin
The lowermost layer of skin is fat cell layer. This layer helps in conserving heat and acts as a shock absorber and helps in protecting inner organs
Image from Wikipedia: Madhero88 and M.Komorniczak (https://commons.wikimedia.org/wiki/File:Skin_layers.svg), „Skin layers“, background by thaneskincentre, https://creativecommons.org/licenses/by-sa/3.0/legalcode