high beam vs light beam

high beam and light beam both are nouns.

Word	Noun	Adjective	Verb	Adverb
high beam	Yes	No	No	No
light beam	Yes	No	No	No

As nouns, light beam is a hypernym of high beam; that is, light beam is a word with a broader meaning than high beam:

high beam: the beam of a car's headlights that provides distant illumination
light beam: a column of light (as from a beacon)

Other hypernyms of high beam include beam, beam of light, irradiation, ray, ray of light, shaft, shaft of light.

high beam (noun)	light beam (noun)
the beam of a car's headlights that provides distant illumination	a column of light (as from a beacon)