In BDSM, Master/slave or M/s is a relationship in which one individual (the submissive) gives to another (the dominant) ultimate authority over them. It is a form of dominance and submission. The participants may be of any gender or sexual orientation. The relationship is structured in terms of slavery, because of the association of the term with ownership of the slave and the rights of a master to their body, as property or chattel. The dominant is often called Master if male, or Mistress if female.
The owner/slave relationship is entered into on a consensual basis, without the legal force of historical or modern non-consensual slavery, which is forbidden by the laws of most countries.