Definition - What does DVD-RAM mean?
DVD-RAM is a portable, removable and rewritable optical disc format. Unlike the standard DVD medium, DVD-RAM can be written, erased and/or overwritten (with a maximum overwrite capacity of 100,000). The format uses phase change recording, in which alternating laser intensity changes the discs’ record layers to and from various physical states, and is only compatible with devices that are specifically manufactured to support it.
Techopedia explains DVD-RAM
The DVD-RAM format was first presented by the DVD Forum in 1996 and the first DVD-RAM drive was introduced by Panasonic two years later. Since its origin, the medium has been available as single- and double-sided discs. DVD-RAM drives are typically able to also read DVD-ROM, standard DVDs and all different forms of compact disc. There now exist at least a dozen different specifications for the format, with a wide range of recording speeds and storage capacities.