Dogs: Man’s Best Friend

Dogs fill a variety of roles in human society. Working dogs of all kinds do traditional jobs such as herding and new jobs such as detecting contraband, and helping the blind. For dogs that do not do their traditional jobs, a wide range of dog sports provide the opportunity to exhibit their natural skills. In many countries the most common and perhaps most important role of dogs is as companions. Dogs have lived with and worked with humans in so many roles that they have earned the sobriquet "man's best friend".

Terminology of Dogs
Dog, in common usage, refers to the domestic dog, Canis lupus familiaris (originally classified as Canis familiaris by Linnaeus in 1758, but reclassified as a subspecies of the wolf, Canis lupus, by the Smithsonian Institution and the American Society of Mammalogists in 1993). The word is sometimes used to refer collectively to any mammal belonging to the family Canidae (as in "the dog family"), such as wolves, foxes and coyotes.

Dog is also a term used by breeders to specifically denote a male domestic dog. The female is known as a bitch. A young dog is called a puppy. The words pooch and poochie are generic, generally affectionate terms for a dog. Many additional terms are used for dogs that are not purebred; see Terms for mixed-breed dogs. Toy dogs are so called because of their small size.