The term "Pit Bull" correctly refers to the American Pit Bull Terrier (APBT) breed of dogs. This pure-breed is recognized by the United Kennel Club (UKC) and the American Dog Breeders Association (ADBA). The American Kennel Club (AKC) recognizes a breed known as the American Staffordshire Terrier (AmStaff). Both the UKC and ADBA recognize the AmStaff as an American Pit Bull Terrier.

The media, legislators, and others use the term "Pit Bull" incorrectly to describe a wide group of dogs which include several distinct breeds and types. Included in this group are American Pit Bull Terriers, American Staffordshire Terriers, and Staffordshire Bull Terriers. Often, Bull Terriers, American Bulldogs, and countless mixed-breed dogs with characteristics similar to any one of these breeds are included under this mis-named group. As a result, many people are confused about what a "Pit Bull" actually is, since the popular public definition is so wide and the breeds above actually share similar bloodline history and physical characteristics.

This broad and incorrect use of the term "Pit Bull" is a fairly recent development, and seemingly the roots of the redefinition lie with the misinformed media. Along with the myriad myths propagated by careless reporting came misapplication of the nickname "Pit Bull". The American Pit Bull Terrier is the only breed with the words "pit" and "bull" actually in its name, and the only one of the above breeds/types that is most commonly, correctly, and historically, called a "Pit Bull".