"Pit bull" is a generic term that includes a variety of breeds, including the American pit bull terrier, Staffordshire terrier and American Staffordshire terrier. However, the American pit bull terrier is the only breed that includes the full term in its name.
Since "pit bull" is a colloquial term, there is no official definition for it. However, most dogs described as pit bulls are medium-sized, muscular animals. They tend to have a broad chest and powerful hindquarters, with long, thin tails. Their heads are large and broad, and their ears are somewhat short and floppy. They tend to be friendly, outgoing dogs that are eager to please their owners, but they often have high energy levels and may have high prey drives. Due to their historical use in dog fighting, some pit bulls have a naturally high level of aggression toward other dogs.
As of 2015, many people also distinguish between red-nose and blue-nose pit bulls. However, these dogs are part of the same breed. The terms traditionally refer to specific bloodlines, but may also be used to refer to appearance.