BDSM is a variety of erotic practices involving dominance and submission, role-playing, restraint, and other interpersonal dynamics. Given the wide range of practices, some of which may be engaged in by people who don't consider themselves as practicing BDSM, inclusion in the BDSM community and/or subculture is usually dependent on self-identification and shared experience. Interest in BDSM can range from one-time experimentation to a lifestyle, and there is debate over whether a BDSM or kink sexual identity also constitutes a form of sexual orientation.
The term BDSM dates back to 1969, however the origin of the term BDSM is unclear, and is believed to have been formed either from joining the term B&D (bondage and discipline) with S&M (sadomasochism or sadism and masochism), or as a compound initialism from B&D, D&S (dominance and submission), and S&M. Regardless of its origin, BDSM is used as a catch-all phrase to include a wide range of activities, forms of interpersonal relationships, and distinct subcultures. BDSM communities generally welcome anyone with a non-normative streak who identifies with the community; this may include cross-dressers, extreme body mod enthusiasts, animal players, latex or rubber aficionados, and others.
Unlike the usual "power neutral" relationships and play styles commonly followed by couples, activities and relationships within a BDSM context are often characterized by the participants' taking on complementary, but unequal roles; thus, the idea of informed consent of both the partners becomes essential. Participants who exert sexual control over their partners are known as Dominants or tops while participants who take the passive, receiving, or obedient role are known as submissives or bottoms. Individuals are also sometimes abbreviated when referred to in writing, so a Dominant person may be referred to as a Dom for a man, and a Domme for a woman. Dom/Dommes are typically referred to in upper case when written about, while subs are in lower case. Individuals who alternate between top/Dominant and bottom/submissive roles – whether from relationship to relationship or within a given relationship – are known as switches, though the term is occasionally seen as derogatory and is rejected by many who might simplistically fit the definition. Precise definition of roles and self-identification is a common subject of debate, reflection, and discussion within the community.