Casein is a type of protein found primarily in milk and dairy products. It makes up about 80% of the protein content in cow's milk and is responsible for the white color of milk. Casein is known for its slow digestion, which provides a steady release of amino acids into the bloodstream, making it popular among athletes and bodybuilders for muscle recovery. In addition to its nutritional benefits, casein is used in various food products, such as cheese and yogurt, due to its ability to form gels or curds. It is also utilized in non-food applications, including adhesives and paints, highlighting its versatility beyond the kitchen.