luminescence vs brightness

luminescence and brightness both are nouns.

Word	Noun	Adjective	Verb	Adverb
luminescence	Yes	No	No	No
brightness	Yes	No	No	No

As nouns, brightness is a hypernym of luminescence; that is, brightness is a word with a broader meaning than luminescence:

Other hypernyms of luminescence include brightness level, light, luminance, luminosity, luminousness.

luminescence (noun)	brightness (noun)
light from nonthermal sources	the location of a visual perception along a continuum from black to white
light not due to incandescence; occurs at low temperatures	the quality of being luminous; emitting or reflecting light
	intelligence as manifested in being quick and witty