Border collie vs shepherd dog

Border collie and shepherd dog both are nouns.

Word	Noun	Adjective	Verb	Adverb
Border collie	Yes	No	No	No
shepherd dog	Yes	No	No	No

As nouns, shepherd dog is a hypernym of Border collie; that is, shepherd dog is a word with a broader meaning than Border collie:

Border collie: developed in the area between Scotland and England usually having a black coat with white on the head and tip of tail used for herding both sheep and cattle
shepherd dog: any of various usually long-haired breeds of dog reared to herd and guard sheep

Other hypernyms of Border collie include sheep dog, sheepdog.

Border collie (noun)	shepherd dog (noun)
developed in the area between Scotland and England usually having a black coat with white on the head and tip of tail used for herding both sheep and cattle	any of various usually long-haired breeds of dog reared to herd and guard sheep