Original: Their styles, textures and flavors depend on the origin of the milk (including the animal's diet), whether they have been pasteurized, the butterfat content, the bacteria and mold, the processing, and aging.
Simplified: Their different styles and flavors depend on the origin of the milk and whether it has been pasteurized. It also depends on the butterfat content, the species of bacteria and mold, and the processing including the length of aging.