In contrast, a "portable DVD player" is a self ... may play only the minus group (DVD-R, DVD-RW). DVD players may also read and write DVD-RAM discs, but compatibility between brands is not guaranteed.

See DVD drives, DVD-R, DVD-RW, DVD+R and DVD+RW. (2) A stand-alone DVD player for TV viewing that also records DVDs on blank DVD-R discs or DVD+R discs. The device may also record on one or more ...

CD-RW - meaning CD-ReWritable, the CD can be written and re-written to. Unlike multi-session discs, existing data can be overwritten. DVD-ROMs - read only, the data is written to them before they ...