The term APSO is an acronym for the Lhasa Apso, a breed of dog originating from Tibet. The Lhasa Apso is a small, long-haired breed of dog that is known for its loyalty and intelligence. It is a popular companion dog and is often used as a guard dog. The breed is also known for its distinctive coat, which can be either straight or wavy. The Lhasa Apso is a hardy breed that is well suited to both indoor and outdoor living.