The largest organ in the human body is the skin. It covers the entire body and acts as a protective barrier against germs, chemicals, and physical injuries. The skin also helps regulate body temperature by sweating and controlling blood flow. It allows us to feel touch, pain, heat, and cold through many tiny nerve endings. The skin is made up of three layers: the epidermis (outer layer), dermis (middle layer), and hypodermis (inner layer). Besides protection, the skin helps in making vitamin D when sunlight touches it. Unlike other organs like the liver or heart, which have specific functions inside the body, the skin protects everything inside the body. It also prevents water loss and helps keep the body safe from the outside world. Because of its size and important functions, the skin is truly the largest and one of the most vital organs.