There are currently 5 types:

  1. DVD TYPE I – 5.2 GB (double sided, 2.6 GB per side)
  2. DVD TYPE II – 2.6 GB
  3. DVD TYPE I – 9.4 GB (double sided, 4.7 GB per side)
  4. DVD TYPE II – 4.7 GB
  5. Cartridge-less (disk only) 4.7 GB

DVD-RAM TYPE I is a double sided disk – when one side is full, you can flip it over and use the second side. DVD RAM TYPE II is a single sided disk. The disk can be removed from its carrier and be used in a computer’s DVD-ROM drive.