Individual folklore artifacts are commonly classified as one of three types: material, verbal or customary lore. For the most part self-explanatory, these categories include physical objects (material folklore), common sayings, expressions, stories and songs (verbal folklore), and beliefs and ways of doing things (customary folklore). There is also a fourth major subgenre defined for children's folklore and games (childlore), as the collection and interpretation of this fertile topic is peculiar to school yards and neighborhood streets. Each of these genres and their subtypes is intended to organize and categorize the folklore artifacts; they provide common vocabulary and consistent labeling for folklorists to communicate with each other.