A snap case is a type of optical disc packaging. It consists of a paperboard flap (where the cover art is printed) which is held closed by a narrow plastic strip which has a "snap" closure. The strip is part of a single piece of plastic which forms the disc tray, and protective edges at the top and bottom. The "hinge" is simply created by the thinness of the plastic along the back right corner. The closure forms the right edge of the package and wraps as a single rigid piece around to the front in an L shape (as viewed from either end). Bumps on the inside of the top and bottom edges of the tray fit into notches on the end of the closure in order to create the snap.
The packaging was created both to be less expensive and to be more eco-friendly. However, in response to criticisms regarding its somewhat fragile design, the snap case has been largely replaced by the keep case for DVD, and the CD jewel case (which came well before and has lasted long since the snap case).
Warner Brothers, New Line Cinema, Columbia TriStar (for its first few titles), and Live Entertainment were four of the few major film studios to release DVDs in this packaging but have slowly phased-in the keep case on their films. Snap cases are often the packaging of choice for discounted DVD rereleases.