soft-cover book

NOUN
15 LETTERS · STARTS WITH S

soft-cover book is a valid 15-letter word worth 27 points in Scrabble and 30 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
S1O1F4T1-0C3O1V4E1R1B3O1O1K5
1 + 1 + 4 + 1 + 0 + 3 + 1 + 4 + 1 + 1 + 0 + 3 + 1 + 1 + 5 =27 PTS
DOUBLE WORD → 54TRIPLE WORD → 81
MEANING

What does soft-cover book mean?