cdrwin only does dao (disc at once)
tao (track at once) is where each track of the disc is burnt then the lead in and out are burnt the spacing is somwhow difference to dao but i cant remember how exactly, i just remember that some sega cd/megacd stuff (lunar for example) is better burnt in tao
dao is when the disc is written as leadin, tracks, then leadout, there is some other difference to the final product when compared to tao to do with the track spacing, but as i said above im not exactly sure what the difference is