the CD coding are the same so CD's are universal...
(unless you get into FILE CD's then it can get a bit complicated but usually that won't matter)

DVD codings are different because it involves all these different MOVIE files...

just right off the top of my head, you've got .avi files, .vob files .dv files .MPEG files and in the MPEG files alone you have MPEG1 to MPEG10 to MPEG to the X

then, you have different Region Codes for DVD, US and Canada have region 1 and I think Australia DVD is region 2 and so on and so forth, so DVD's are not universal....

a person can make backup copies of whatever they own. If you own the DVD, Mrs. D, it is NOT illegal...it would be IF you sell it to me...LOL

I like that program Lara suggested and there are few other ones also. IF that one doesn't work for you, there are a couple of others...