shortness vs briefness

shortness and briefness both are nouns.

Word	Noun	Adjective	Verb	Adverb
shortness	Yes	No	No	No
briefness	Yes	No	No	No

As nouns, briefness is a hyponym of shortness; that is, briefness is a word with a more specific, narrower meaning than shortness:

Other hyponyms of shortness include curtailment.

shortness (noun)	briefness (noun)
an abrupt discourteous manner	the attribute of being brief or fleeting
the property of being shorter than average stature	the temporal property of being very short
the property of being of short temporal extent
the property of being of short spatial extent
the property of being truncated or short
the condition of being short of something