To me,apart from the price, it seems that DVD-R is only single session (I don't know what that means, someone please explain) and the DVD+R are multisession. My Newbie explanation to this is that DVD-R doesn't let you copy the content on the DVD and DVD+R let's you copy as much as you want. I tested this using Imation DVD-R for my PS2 and Movie backups and i wanted to make an extra copy and it wouldn't let me. I then used the same brand but DVD+R and it copied with no fuss. BTW my dvd burner is a Sony DW-D22A and I used Nero to burn (and try to burn) the images. Someone please give me even a half descent explanation, I know it sounds complicated but a lot of thanks for any replies in advance.