Porn movies movies explicitly depict sexual intercourse and other sexual acts, for the purpose of sexual arousal in the viewer.

They appeared shortly after the creation of the movie technology that made them possible.

All other forms of pornography and porn movies have much in common. Pornography is often referred to as "porn" and a pornographic work as "a porno”.
Older names for porn movies include "adult film", "stag film", and "blue movie”.

In some countries or states movie theaters (or sex cinema) specialized in showing porn movies are allowed by law.

There are various subjects that are common in porn movies today. These sex acts are typically presented in a ritualized manner not representative of common sexual behavior.

Current porn movies can be divided into a number of sub-genres by the sex of the performers, the types of sex act portrayed, and the intended audience.

Porn movies are notable for their extensive use of sequels, probably due to the lack of plot: a successful new movie will often generate dozens of numbered sequels in essentially the same format.