Some are the same, some overlap. Here are some of the differences that I remember:
DVC members get 20% off at most of the restaurants in the Swan & Dolphin Resorts -very handy if you are staying at the BWV or BCV.
DVC members get a great discount on the APs and PAPs.
If you have an AP or PAP, you can purchase the Tables In Wonderland (TIW) dining discount card, formerly known as the Disney Dining Experience. That gets you a 20% discount on food and beverage, including alcoholic drinks, at most on site TS restaurants.
APs/PAPs entitle you to free parking at the theme parks.
Those are the major differences that I can think of. PP already mentioned the discount at WOD. Most, not all, of the dining discounts are the same and most are 10% off a lunch.