sheepdog vs briard

sheepdog and briard both are nouns.

Word	Noun	Adjective	Verb	Adverb
sheepdog	Yes	No	No	No
briard	Yes	No	No	No

As nouns, briard is a hyponym of sheepdog; that is, briard is a word with a more specific, narrower meaning than sheepdog:

sheepdog: any of various usually long-haired breeds of dog reared to herd and guard sheep
briard: old French breed of large strong usually black dogs having a long tail and long wavy and slightly stiff coat

sheepdog (noun)	briard (noun)
any of various usually long-haired breeds of dog reared to herd and guard sheep	old French breed of large strong usually black dogs having a long tail and long wavy and slightly stiff coat