DVD disc types
The purpose of this article is to provide a quick introduction to the most common DVD types. Notice that it's essential to understand these formats before starting to burn DVD discs.
DVD stands for Digital Versatile Disc (or Digital Video Disc) and it was designed for digital media storage, more specifically for replacing the previous VHS and SVHS technology.
DVD physical structure
A DVD is basically a CD with larger capacity; but the DVD has two major attributes that makes it different from the CD: The ability to store data on both sides of the disc, and with dual data layers on each side as well. The total DVD capacity ranges from 4.7 to 17.1 GB, according to the type of disc, the later being a double-sided and double-layered disc.
Internal DVD structure
DVD capacities and disc types
* The indicated disc capacities are higher than the useable ones because they consider each GB as 1000 MB, while in computers 1 GB equals to 1024 MB.
** The DVD-14 is a double sided disc, one of them is single layer while the other is dual layer. This one and DVD-18 are extremely hard to manufacture and are for all practical purposes not available commercially.
DVD-5 (4.38 GB, SS-SL)
The DVD-5 is the simplest type of disc, because it features and unique data layer on one of its sides, using the opposite side for labeling of the disc. Its effective capacity is 4.38 GB, and its structure is identical to the used in the CD.
DVD-9 (7.92 GB, SS-DL)
The single sided, dual layer DVD-9 features two reflective surfaces on the same side of the disc, and this provides almost twice the capacity of the single layered DVD-5. The reading laser can read each layer independently. This provides 7.92 GB for data storage.
Its capacity is slightly smaller than twice the single layer version because its pits are 10% longer to make the second layer easier to read. This disc can be have a label on the unused side.
DVD-10 (8.76 GB, DS-SL)
The DVD-10 disc uses both sides to store data, each of them with a single reflective layer. Its capacity doubles the one from the DVD-5. To playback the other side of the disc, the disc must be extracted and turned over in most drives.
Since both sides of the disc contain data, the label printing can only be done on a thin ring in the center of the disc.
DVD-18 (15.9 GB, DS-DL)
DVD-18 provides the highest capacity of the DVD family, because it stores data on both sides using a dual layer structure on each of them. This provides almost 16 GB for effective storage.
This type of DVD is the most complex to manufacture, because the four data layers must be stamped on the same substrate. In the DVD-Video family, these discs usually contain a movie in Widescreen on one of its sides and the Fullscreen version on the other side.