Final Fantasy is a media franchise created by Hironobu Sakaguchi and owned by Square Enix that includes video games, motion pictures, and other merchandise. The series began in 1987 as an eponymous console role-playing game (RPG) developed by Square, spawning a video game series that became the central focus of the franchise. The franchise has since branched out into other genres and platforms, such as tactical RPG's, portable games, a massively multi player online role-playing game, and games for mobile phones. As of March 2007, there are twenty-eight games in the franchise—including twelve numbered games and numerous spin-off titles.The series has spurred the release of three animated productions, two full-length CGI films, and several printed adaptations.
Most Final Fantasy installments are independent stories (the numbers after the title refers more to volumes than sequels); however, they feature common elements that define the franchise. Such elements include recurring creatures, character names, airships and character classes. The series has popularized many features that are now widely used in console RPG's, and it is well known for its visuals, music, and innovation. For example, the inclusion of full motion videos, photo-realistic character models, and orchestrated music by Nobuo Uematsu. The series have been commercially and critically successful; it is the fourth-best-selling video game franchise, with more than 80 million units sold as of December 2007. Many individual titles in series have garnered extra attention and their own positive reception. In addition, the series was awarded a star on the Walk of Game in 2006.

My source was wikipedia.