Direct-to-video or 2013's "Sharknado". As DVDs gradually replaced VHS videocassettes, the term "direct-to-DVD" replaced "direct-to-video" in some instances. However, the word "video" does not necessarily refer to videocassettes; many publications continue to use the term "direct-to-video" for DVDs or Blu-ray discs. Both disc-based release types may also be referred to as "direct-to-disc". A new term sometimes used is "DVD premiere" (DVDP). Such films can cost as little as $20 million, about a third of the average cost of a Hollywood release. According to "Variety", "" sold a million copies in one week, despite retaining only two actors from the original trilogy.
DVD-RAM The on-disc structure of DVD-RAM is closely related to hard disk and floppy disk technology, as it stores data in concentric tracks. DVD-RAMs can be accessed just like a hard or floppy disk and usually without any special software. DVD-RWs and DVD+RWs, on the other hand, store data in one long spiral track and require special packet reading/writing software to read and write data discs. Like magneto-optical (MO) technologies, DVD-RAM has numerous rectangles on the disc surface that define the boundaries of data sectors. However, DVD-RAM is not MO but a phase transition medium, similar to CD-RW, DVD-RW, or DVD+RW.