blank space vs surface area

blank space and surface area both are nouns.

Word	Noun	Adjective	Verb	Adverb
blank space	Yes	No	No	No
surface area	Yes	No	No	No

As nouns, surface area is a hypernym of blank space; that is, surface area is a word with a broader meaning than blank space:

blank space: a blank area
surface area: the extent of a 2-dimensional surface enclosed within a boundary

Other hypernyms of blank space include area, expanse.

blank space (noun)	surface area (noun)
a blank area	the extent of a 2-dimensional surface enclosed within a boundary