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.
Optical disc drive on personal computers was originally a batch-oriented task in that it required specialised authoring software to create an "image" of the data to record, and to record it to disc in the one session. This was acceptable for archival purposes, but limited the general convenience of CD-R and CD-RW discs as a removable storage medium. Packet writing is a scheme in which the recorder writes incrementally to disc in short bursts, or packets. Sequential packet writing fills the disc with packets from bottom up. To make it readable in CD-ROM and DVD-ROM drives, the disc can be "closed" at any