A string dog is neither a native dog nor a pet dog. It's a hybrid dog. Cross-line dogs refer to all cross-bred dogs or dogs with inconspicuous breed characteristics, not a specific dog breed, and their genes are impure, mainly distributed all over the world. Local dogs, the full name of Chinese Garden Dogs, are mainly distributed in low-altitude areas south of the Great Wall of China, east of the Qinghai-Tibet Plateau and centered on the central region, and widely exist in rural areas of China and Southeast Asia. Pet dogs refer to dogs kept by people for the purpose of eliminating loneliness or entertainment, or dogs kept for non-economic purposes, such as Golden Retriever, Labrador, Alaska, etc.