dvd5 single layer.,., 4.7Gb

dvd9 dual layer,., 9Gb

pdvd / r5 .. pre/pirated dvds for low quality., good for watching but should wait for original dvd to come out to keep for own collection...

Original dvds come in DVD9 (dual layer .. 9Gb) DVDs...

there is good guide / faq when to download and which format means which.. ie cam/ ts/ r5 etc etc etc...

hope it helps