A puppy is a juvenile dog. Some puppies can weigh 1–1.5 kg (2.2–3.3 lb), while larger ones can weigh up to 7–11 kg (15–24 lb). All puppies display primary altriciality and healthy puppies grow quickly after birth. A puppy's coat color may change as the puppy grows older, as is commonly seen in breeds such as the Yorkshire Terrier. Puppy refers specifically to young dogs, while pup may be used for other animals such as wolves, seals, giraffes, guinea pigs, rats or sharks.

The dog is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from extinct gray wolves, and the gray wolf is the dog's closest living relative. The dog was the first species to be domesticated by humans. Experts estimate that hunter-gatherers domesticated dogs more than 15,000 years ago, which was before the development of agriculture. Due to their long association with humans, dogs have expanded to a large number of domestic individuals and gained the ability to thrive on a starch-rich diet that would be inadequate for other canids.