volcanic rock vs igneous rock

volcanic rock and igneous rock both are nouns.

Word	Noun	Adjective	Verb	Adverb
volcanic rock	Yes	No	No	No
igneous rock	Yes	No	No	No

As nouns, igneous rock is a hypernym of volcanic rock; that is, igneous rock is a word with a broader meaning than volcanic rock:

volcanic rock: extrusive igneous rock solidified near or on the surface of the Earth
igneous rock: rock formed by the solidification of molten magma

volcanic rock (noun)	igneous rock (noun)
extrusive igneous rock solidified near or on the surface of the Earth	rock formed by the solidification of molten magma