The production of cheese, like many other food preservation processes, allows the nutritional and economic value of a food material, in this case milk, to be preserved. It allows the consumer to choose (within limits) when to consume the food rather than have to consume it straight away, and it allows the product to be altered which gives it higher value.
Cheesemaking may have originated from nomadic herdsmen who stored milk in vessels made from the sheep's and goats' stomachs. Because their stomach linings contains a mix of lactic acid, wild bacteria as milk contaminants and rennet, the milk would ferment and coagulate. A product reminiscent of yogurt would have been produced, which, through gentle agitation and the separation of curds from whey would have resulted in the production of cheese; the cheese being essentially a concentration of the major milk protein, casein, and milk fat. The whey proteins, other minor milk proteins, and the lactose are all removed in the cheese whey.
The job of the cheesemaker is to control the spoiling of milk into cheese. The milk may be from a cow, goat, sheep or buffalo, although worldwide cow's milk is most commonly used. The cheesemaker applies craft and skill to the practise of cheesemaking, intending to produce a product with specific characteristics and organoleptic requirements (appearance, aroma, taste, texture) that are consistent every time it is made. This is not to say, of course, there is no room for variety or innovation, but a particular cheese needs to be made a particular way. Thus, the crafts and skills employed by the cheesemaker to make a Camembert will be similar to, but not quite the same as, those used to make Cheddar.