Video on demand (VOD) is a video media distribution system that allows users to access video entertainment without a traditional video entertainment device and without the constraints of a typical static broadcasting schedule. In the 20th century, broadcasting in the form of over-the-air programming was the commonest form of media distribution. As Internet and IPTV technologies continued to develop in the 1990s, consumers began to gravitate towards non-traditional modes of content consumption, which culminated in the arrival of VOD on televisions and personal computers.
Unlike broadcast television, VOD systems initially required each user to have an Internet connection with considerable bandwidth to access each system's content. In 2000, the Fraunhofer Institute IIS developed the JPEG2000 codec, which enabled the distribution of movies via Digital Cinema Packages. This technology has since expanded its services from feature-film production to include broadcast television and has resulted in lower bandwidth requirements for VOD applications. Disney, Paramount, Sony, Universal and Warner Bros. subsequently launched the Digital Cinema Initiative, in 2002.
Television VOD systems can stream content, either through a traditional set-top box or through remote devices such as computers, tablets, and smartphones. VOD users can permanently download content to a device such as a computer, digital video recorder or a portable media player for continued viewing. The majority of cable and telephone company-based television providers offer VOD streaming, whereby a user selects a video program that begins to play immediately or downloading to a digital video recorder (DVR) rented or purchased from the provider, or to a PC or to a portable device for delayed viewing.
Internet television has emerged as an increasingly popular medium of VOD provision. Desktop client applications such as the Apple iTunes online content store and Smart TV apps such as Amazon Prime Video allow temporary rentals and purchases of video entertainment content. Other internet-based VOD systems provide users with access to bundles of video entertainment content rather than individual movies and shows. The most common of these systems, Netflix, Hulu and Disney+, use a subscription model that requires users to pay a monthly fee for access to bundle of movies, television shows, and original series. In contrast, YouTube, another internet-based VOD system, uses an advertising-funded model in which users can access most of YouTube's video content free of charge but must pay a subscription fee for premium content. Some airlines offer VOD services as in-flight entertainment to passengers through video screens embedded in seats or externally provided portable media players.