racetrack vs dirt track

racetrack and dirt track both are nouns.

Word	Noun	Adjective	Verb	Adverb
racetrack	Yes	No	No	No
dirt track	Yes	No	No	No

As nouns, dirt track is a hyponym of racetrack; that is, dirt track is a word with a more specific, narrower meaning than racetrack:

Other hyponyms of racetrack include cinder track, circuit, racing circuit, speedway, velodrome.

racetrack (noun)	dirt track (noun)
a course over which races are run	a racetrack that is not paved