Puppy

A puppy is a juvenile dog, usually less than one year of age. The term is sometimes abbreviated to pup, a term which is also used for the offspring of wolves.
Puppies are very playful and active. A lethargic or listless puppy is unusual, and often times a precursor to illness.

Types
Some breeds traditionally have their tails docked or ears cropped, or both. Many countries now ban cropping and docking for cosmetic purposes, but other countries have no such prohibitions. Some breeders favor to remove a dog's dewclaws to prevent future injuries. These procedures are usually performed within the first few days after birth, by a veterinarian, or by an experienced breeder.
Size varies among breeds, some puppies are 1-3lbs, while others are 15-20lbs. Coats can change color as the puppy grows older, this is commonly seen in breeds such as the Yorkshire Terrier.