Nope — each Couch Skin covers one cushion. They're individual covers that fit over each seat cushion, back cushion, or chaise cushion. Not a one-piece full-sofa slipcover.
Depending on your couch, you may need a few. A 3-seat sofa, for example, might need 3 seat covers and 3 back covers. When you order, you pick covers for the number and type of cushions your couch has.