​​Each breed of dog recognized by a dog registry, such as the American Kennel Club, has a written description called a "standard." The standard is a verbal picture of the ideal dog for that breed, describing every aspect of its appearance and demeanor in detail. This includes ideal structure, temperament, movement and type. It is written by people with expert knowledge of the breed, usually a club or committee composed of long-time breeders, exhibitors and judges. When a dog competes in a dog show, it is judged not only against the other dogs of its breed competing that day, but also against the written standard. The dog that wins is the one closest, in the judge's opinion, to the standard for its breed. The standard is also used to choose dogs for breeding. Breeders use the standard as a guideline to determine which dogs (boys) or bitches (girls) should pass on their genes to future generations.
- The Essential Australian Shepherd