Main differences here are sizes vs. devices. I adhere to responsive design here at my day job. However, this site and other I create are based on adaptive design principles. They are both great ways to deliver content to users with little maintenance. But the nitty gritty suggests there are issues in performance, scalability, and delivery methods that make these two even more distinct. I left a few articles for you knuckle heads to read!
For more, see the article by Ryan Boudreaux
Cool photo on this topic: