Cheese is basically a concentrated source of the nutrients found in the milk from which it was made. Milk itself is regarded as a nearly complete food.  

The basic principles of cheese making are the same for all natural cheeses. The object is to extract the water from milk, leaving the milk solids. Cheese consists of the milk protein casein, nearly all of the fat and fat-soluble vitamins of the original milk, minerals such as calcium and varying amounts of entrapped moisture. This entrapped moisture contains the water-soluble constituents of milk such as lactose, whey protein, soluble salts, vitamins and other minor milk components. Because of its nutrient content, cheese is generally described as a nutrient dense food.  

Cheese is also defined as a high-quality protein. This means that it's more than just a complete protein, which is a protein that contains all the essential amino acids in amounts adequate for human use; it may or may not contain other amino acids. High-quality protein means that cheese contains the essential amino acids in amounts proportional to the body's need for them and is digestible, so that sufficient amounts of these amino acids reach the body's cells to permit them to make the proteins they need.  

When proteins are consumed, they assist with building and repairing body tissue; they form antibodies, hormones and enzymes; and provide energy.