northern pin oak vs oak

northern pin oak and oak both are nouns.

Word	Noun	Adjective	Verb	Adverb
northern pin oak	Yes	No	No	No
oak	Yes	No	No	No

As nouns, oak is a hypernym of northern pin oak; that is, oak is a word with a broader meaning than northern pin oak:

northern pin oak: small to medium deciduous oak of east central North America; leaves have sharply pointed lobes
oak: a deciduous tree of the genus Quercus; has acorns and lobed leaves

Other hypernyms of northern pin oak include oak tree.

northern pin oak (noun)	oak (noun)
small to medium deciduous oak of east central North America; leaves have sharply pointed lobes	a deciduous tree of the genus Quercus; has acorns and lobed leaves
	the hard durable wood of any oak; used especially for furniture and flooring