The pornography industry in the United States was the first to develop its own movie star system, primarily for commercial reasons. Most actors specialize in certain genres, such as straight sex, bisexual sex, gay sex, lesbian sex, bondage, strap-on sex, anal sex, double penetration, semen swallowing, teenage women, orgy sex, age roleplay sex, fauxcest sex, interracial or MILFs and much more. Depending on the genre of the film, the on-screen appearance, age, and physical features of the main actors and their ability to create the sexual mood of the video is of critical importance. The genres and sexual intensity of videos is mainly determined by demand. Pornographic videos are characterised as either softcore, which does not contain depictions of sexual penetration or extreme fetishism, and hardcore, which can contain depictions of penetration or extreme fetishism, or both. Such videos tend to be made in a number of distinct pornographic subgenres and attempt to present a sexual fantasy the actors selected for a particular role are primarily selected on their ability to create or fit that fantasy. A pornographic film actor or actress, adult entertainer, or porn star is a person who performs sex acts in video that is usually characterized as a pornographic movie.
