From the AKC (www.akc.org)

Dog shows, or "conformation" events, are the signature events of the AKC. They concentrate on the distinctive features of purebred dogs and help to preserve these characteristics by providing a forum at which to evaluate breeding stock.

Exhibits are judged against individual breed standards, which have been established for the AKC-recognized breeds by their parent clubs. These written standards describe the ideal size, color, and temperament of each breed, as well as correct proportion, structure, and movement.