Milk is a white, nutrient-rich liquid that mammals, including humans, produce to feed their young offspring. It is a primary source of nutrition for newborns before they are able to digest solid food. In the context of human consumption, milk usually refers to cow's milk, although milk from other mammals such as goats, sheep, and buffalo is also consumed in various parts of the world. Milk is a complete food, containing a balanced mix of proteins, carbohydrates, fats, vitamins, and minerals. It is an excellent source of calcium, which is essential for bone and teeth health. Milk also contains proteins like casein and whey, which are rich in essential amino acids, making it a good source of high-quality protein. Additionally, milk is fortified with vitamin D in many countries, which is crucial for calcium absorption in the body.