system function

15 LETTERS · STARTS WITH S

system function is a valid 15-letter word worth 24 points in Scrabble and 28 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

S1Y4S1T1E1M3F4U1N1C3T1I1O1N1

1 + 4 + 1 + 1 + 1 + 3 + 0 + 4 + 1 + 1 + 3 + 1 + 1 + 1 + 1 =24 PTS

DOUBLE WORD → 48TRIPLE WORD → 72

MEANING

What does system function mean?