Pornography (frequently abbreviated porn) is the portrayal of sexual subject matter for its exclusive purpose of sexual arousal. Pornography may be presented in a variety of media, such as books, magazines, postcards, photographs, sculpture, drawing, painting, animation, audio recording, phone calls, writing, film, movie, and video games. The term applies to the depiction of this action rather than the act itself, and so doesn't include live arenas such as gender shows and striptease. The main subjects of present-day pornographic depictions are pornographic models, that present for still photographs, and pornographic actors or porn stars, who play in pornographic films. If dramatic skills aren't involved, a performer in a porn film may also be known as a model. Various groups within society have believed depictions of a sexual nature immoral, addictive, and poisonous, labeling them and attempting to get them suppressed under obscenity and other laws, with varying levels of success. Such functions also have often been subject to censorship and other legal restraints to book, screen, or ownership, leading in many cases to their loss. Such grounds, and even the definition of porn, have differed in different historical, cultural, and national contexts.