moon-ray vs ray of light

moon-ray and ray of light both are nouns.

Word	Noun	Adjective	Verb	Adverb
moon-ray	Yes	No	No	No
ray of light	Yes	No	No	No

As nouns, ray of light is a hypernym of moon-ray; that is, ray of light is a word with a broader meaning than moon-ray:

Other hypernyms of moon-ray include beam, beam of light, irradiation, light beam, ray, shaft, shaft of light.

moon-ray (noun)	ray of light (noun)
a ray of moonlight	a column of light (as from a beacon)