A dog breed is a particular type of dog that was purposefully bred by humans to perform specific tasks, such as herding, hunting, and guarding. Dogs are the most variable mammal on Earth, with artificial selection producing upward of 360 globally recognized breeds. These breeds possess distinct traits related to morphology, which include body size and shape, tail phenotype, fur type, etc., but are only one species of dog. Their behavioral traits include guarding, herding, and hunting, and personality traits such as hypersocial behavior, boldness, and aggression. Most breeds were derived from small numbers of founders within the last 200 years. Because of their adaptability and usefulness to humans, dogs are now the most abundant carnivore species worldwide.
A dog bred will consistently produce the physical traits, movement and temperament that were developed over decades of selective breeding. For each breed they recognize, kennel clubs and breed registries usually maintain and publish a breed standard which is a written description of the ideal specimen of the breed. Other uses of the term breed when referring to dogs include pure breeds, cross-breeds, mixed breeds and natural breeds.
