Discs that are re-writable can be used for multiple recordings once existing data is erased.
DVD±R (DVD Recordable)
Discs can only be used for a single recording. Each new recording is always added at the end of all previous recordings as existing recordings cannot be overwritten.
Editing can be done on DVD±R discs as long as they have not been finalised.
You can also delete unwanted recordings. However, the disc space occupied by the deleted recordings cannot be recovered for further recording.
To play a DVD±R disc on other DVD player, it must be finalised. After this is done, no more data can be added to the disc.
DVD+R DL (DVD+R Double Layer)
Like the DVD+R, these discs can only be used for a single recording. The only difference is the capacity- 8.5GB. It offers two recordable layers on a single DVD disc. The layers are accessible from the same side of the disc, so recording can occur completely uninterrupted.