Casein is a type of protein found in milk and dairy products, making up about 80% of the protein content in cow's milk. It is a slow-digesting protein, which means it provides a steady release of amino acids into the bloodstream over several hours. This characteristic makes it popular among athletes and bodybuilders for muscle recovery and growth. In addition to its nutritional benefits, casein is used in various food products, such as cheese and yogurt, to improve texture and flavor. It is also utilized in non-food applications, including adhesives and paints, due to its binding properties.