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 rotation (Constant linear velocity (CLV), Constant angular velocity (CAV), or zoned-CAV), the composition of lands and pits, and how much margin is unused is at the center and the edge of the disc. Second-generation optical discs were for storing great amounts of data, including broadcast-quality digital video. Such discs usually are read with a visible-light laser (usually red); the shorter wavelength and greater numerical aperture allow a narrower light beam, permitting smaller pits and lands in the disc. In the DVD format, this allows 4.7 GB storage on a standard 12 cm, single-sided, single-layer disc; alternatively, smaller media, such as