knowledge domain

NOUN
16 LETTERS · STARTS WITH K

knowledge domain is a valid 16-letter word worth 27 points in Scrabble and 32 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
K5N1O1W4L1E1D2G2E1D2O1M3A1I1N1
5 + 1 + 1 + 4 + 1 + 1 + 2 + 2 + 1 + 0 + 2 + 1 + 3 + 1 + 1 + 1 =27 PTS
DOUBLE WORD → 54TRIPLE WORD → 81
MEANING

What does knowledge domain mean?