A pornographic film actor or actress, pornographic performer, adult entertainer, or porn star is a person who performs sex acts on video that is usually characterized as a pornographic film. 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. Pornographic videos are characterized 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. The genres and sexual intensity of videos is mainly determined by demand. Depending on the genre of the film, the on-screen appearance, age, and physical features of the actors and their ability to create the sexual mood of the video is of critical importance. Most actors specialize in certain genres, such as straight, bisexual, gay, lesbian, bondage, strap-on, anal, double penetration, semen swallowing, orgy, gang bang, age roleplay, fauxcest, interracial, teenage or MILFs and more.