DVD+/-R's, DVD-RW's generally need to be finalised in order to be able to play them back on another DVD player or on a PC. However, once a disc is finalised, it is no longer possible to edit its content or make further recordings to the disc, however it is still possible to erase or format the disc to reuse it for recordings. DVD+RW's do not need to be finalised in order to play them on other DVD players and even if your DVD recorder can finalise these, like DVD-RW's they can still be formatted or erased.