Collies form a type of herding dogs, including many similar landraces and standardized breeds. The type began in Scotland and Northern England. Collies are usually medium-sized, fairly lightly-built dogs, with pointed noses. Many breeds have a white color over the shoulders. Collies are very active, and most types of collies are excellent at herding. Collie breeds have spread through many parts of the world (especially Australia and North America), and have then made many varieties, sometimes mixed with other dog types (cross breeding, for example, the Borador). Some collie breeds are still used as working dogs for herding cattle, sheep, and other livestock, while others are kept as pets, show dogs or for dog sports, in which they display great agility, stamina and trainability. While the American Kennel Club has a breed they call "collie", in fact "collie dogs" are a type of herding dog including many related landraces and formal breeds. There are usually major differences between show dogs and those bred for herding trials or dog sports: the herding dogs show good agility, stamina and trainability and behaviour.