Prostitution is a type of sex work that involves engaging in sexual activity in exchange for payment. The definition of "sexual activity" varies, and is often defined as an activity requiring physical contact (e.g., sexual intercourse, non-penetrative sex, manual sex, oral sex, etc.) with the customer. The requirement of physical contact also creates the risk of transferring infections. Prostitution is sometimes described as sexual services, commercial sex or, colloquially, hooking. It is also described as gender-based violence. It is sometimes referred to euphemistically as "the world's oldest profession" in the English-speaking world. A person who works in the field is usually called a prostitute or sex worker, but other words, such as hooker and whore, are sometimes used pejoratively to refer to those who work in prostitution. The majority of prostitutes are female and have male clients.
Prostitution occurs in a variety of forms, and its legal status varies from country to country (sometimes from region to region within a given country). In most cases, it can be either an enforced crime, an unenforced crime, a decriminalized activity, a legal but unregulated activity, or a regulated profession. It is one branch of the sex industry, along with pornography, stripping, and erotic dancing. Brothels are establishments specifically dedicated to prostitution. In escort prostitution, the act may take place at the client's residence or hotel room (referred to as out-call), or at the escort's residence or a hotel room rented for the occasion by the escort (in-call). Another form is street prostitution.