There are numerous DVD formats out there, this page will guide you though some of them. Check the details of your system from your invoice to see what formats your drive will support.
Current drives use 4.7 GB discs
DVD-RAM allows fully integrated OS-level random read/write access similar to hard drives as well as on-the-fly write verification. This standard is best for frequent backups since the format is designed to be written to like a hard drive.
The main drawback of the DVD-RAM format is its limited read
compatibility amongst DVD-ROM drives and standalone DVD players. DVD-RAM read support with these units is increasing however, partially because of the increasing popularity of home standalone DVD-RAM recorders in home theatre systems.
DVD-R and DVD-RW
DVD-R and DVD-RW Both use 4.7 GB discs
DVD-R is a write-once recordable format which gives good compatibility with both standalone DVD players and DVD-ROM drives.
DVD-RW media uses rewriteable discs which are rated for more than 1000 rewrites in ideal situations. The majority of standalone DVD players will play video recorded on DVD-RW discs, but the compatibility is not as high as with DVD-R.
DVD+R and DVD+RW
These discs are very similar to DVD-R and DVD-RW in design,
usage, and compatibility.
DVD+RW, like DVD-RW, is a rewriteable 4.7 GB format, and overall it has similar functionality to DVD-RW. The level of compatibility of standard DVD+RW discs in standalone DVD players is similar to that of DVD-RW. The rewritability of DVD+RW is also said to be similar to that of DVD-RW, allowing up to 1000 rewrites.
How come my 4.7 GB disc isn't really 4.7 GB?
Like hard drives, 1 GB on a DVD recordable disc equals 1,000,000,000 bytes. In contrast, a computer considers 1 GB to be 1,073,741,824 bytes. Thus, a 4.7 GB disc is seen by a computer as having approximately 4.37 GB but the number of bytes is the same.