DVD Video

For viewing movies and other visual entertainment. The total capacity is 17 gigabytes if two layers on both sides of the disk are utilized.

DVD-ROM

Its basic technology is the same as DVD Video, but it also includes computer-friendly file formats. It is used to store data. This product should supplant conventional CD-ROMs in the near future.

DVD-R

Its capacity is 4.7 gigabytes. Originally designed for professional authoring, a version for general consumer use is now under development. As with CD-R, users can write only once to this disk.

DVD-RAM

This makes DVD a virtual hard disk, with a random read-write access. Originally a 2.6-gigabyte drive, its capacity has increased to 4.7-gigabyte-per-side. It can be re-written more than 100,000 times.

DVD-RW

Similar to DVD-RAM except that its technology features a sequential read-write access more like a phonograph than a hard disk. Its read-write capacity is 4.7 gigabytes per side. It can be re-written up to about 1,000 times.

DVD Audio

The latest audio format more than doubles the fidelity of a standard CD. It is expected to become the most popular audio disk.