capacity measure

NOUN
16 LETTERS · STARTS WITH C

capacity measure is a valid 16-letter word worth 26 points in Scrabble and 30 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
C3A1P3A1C3I1T1Y4M3E1A1S1U1R1E1
3 + 1 + 3 + 1 + 3 + 1 + 1 + 4 + 0 + 3 + 1 + 1 + 1 + 1 + 1 + 1 =26 PTS
DOUBLE WORD → 52TRIPLE WORD → 78
MEANING

What does capacity measure mean?