Most DVD players play CDs. But there is also a newer standard called DVD audio. Been around for a few years. The issue is trying to find things released in this format.
The construction of a DVD does allow for much more data to be put on the disk, but it woud not be readible on a standard CD player. Personally, I woud use a different format than CDA because CDA is over 10 years old and there are better alternatives.