A Jewel Case is similar in size to a CD case. More expensive DVD players offer more features, such as smoother reverse and fast-forwarding with faster processing. Some offer superior sound with separate optical pickups for playing DVDs and CDs. Parents can access the ratings control through the DVD player's set-up menu. Other ratings are used to correspond with ratings in other parts of the world.
Manufacturers can code DVDs to allow playback only on players set to allow certain ratings levels.
Parents can set their DVDs to limit what ratings their DVD player will play. Release dates for DVDs can change for a variety of reasons. Other times, the manufacturer runs into technical glitches that delay a release. In one recent instance, a slate of scheduled titles was put on hold when ownership of the titles was sold from one studio to another. My DVD player has an internal Dolby Digital decoder.