luminescence vs luminance

luminescence and luminance both are nouns.

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

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

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

luminescence (noun)	luminance (noun)
light from nonthermal sources	the quality of being luminous; emitting or reflecting light
light not due to incandescence; occurs at low temperatures