http://searchstorage.techtarget.com/sDefinition/0,,sid5_gci503648,00.html explains it better than I can
well there are no much different , CD-R can be used for CD-DA , some brands like Maxell or TDK come out with Digital audio , you can use same cd for data or music don't worry, some brands like Creation or samsung made CD-DA but believe me @ the end all same, like you have CD-R , only the look is different (for musician (blue and black is cds are good in my view). don't be fool about price of CD_DA, if it same as CD-R