The Tibetan Terrier is a medium-sized breed of dog that originated in Tibet. Despite its name, it is not a member of the terrier group. The breed was given its English name by European travelers due to its resemblance to known terrier breeds. The Tibetan name for the breed, Tsang Apso, roughly translates to "shaggy or bearded ("apso") dog, from the province of Tsang". Some old travelers' accounts refer to the dog as Dokhi Apso or "outdoor" Apso, indicating a shaggy or bearded working dog which lives outdoors.

A guard dog or watchdog is a dog used to watch for and guard people or property against unwanted or unexpected human or animal intruders.