BDSM is an erotic preference and a form of sexual expression involving the consensual use of restraint, intense sensory stimulation, and fantasy power role-play. The compound acronym BDSM is derived from the terms bondage and discipline (B&D or B/D), dominance and submission (D&S or D/s), and sadism and masochism (S&M or S/M), or sometimes slave and Master/Mistress. BDSM includes a wide spectrum of activities, forms of interpersonal relationships, and distinct subcultures.

Bondage and Discipline

The term “Bondage” describes the practice of physical restraint, typically using rope, straps or chains. Bondage is usually, but not always, a sexual practice. While bondage is a very popular variation within the larger field of BDSM, it is nevertheless sometimes differentiated from the rest of this field. Strictly speaking, bondage means binding the partner by tying their appendages together; for example, by the use of handcuffs or by lashing their arms to an object. Bondage can also be achieved by spreading the limbs and fastening them to furniture.

The term “Discipline” describes the psychological restraint, with the use of rules and punishment to control overt behavior, in the context of a dominant/submissive relationship. Punishment can be pain caused physically (such as caning), humiliation caused psychologically (such as a public humiliation) or loss of freedom caused physically (for example, chaining the Bottom to the foot of a bed). Another aspect is the structured training of the Bottom.

Punishment may not be literal; it may be a pretext for sadomasochism within a fantasy scene.

Service is a form of discipline, in which the submissive person serves the dominant. This can get into subtle distinctions; one submissive may massage their dominant’s feet to derive satisfaction from giving them pleasure, while another may have a foot fetish and derive pleasure from the act itself. 

Dominance and Submission (D&S or D/s)

“Dominance and submission” is a set of behaviors, customs and rituals relating to the giving and accepting of control of one individual over another in an erotic or lifestyle context. It explores the more mental aspect of BDSM. This is also the case in many relationships not considering themselves as sadomasochistic; it is considered to be a part of BDSM if it is practiced purposefully. There is a wide range of types of D/s relationships. It can be a momentary roleplay scene, or a long term commitment. 

Sadism and masochism

The dictionary definitions of sadism and masochism usually involve gaining pleasure from giving and receiving pain. In the context of BDSM, sadism and masochism is better described as consensually giving and receiving intense sensations, not pain per se. A sadist consensually delivers intense sensations in a carefully controlled way to a masochist, up to the masochist’s limits and no further. This could be as intense as cutting the skin or delivering electric shocks, or as mild as tickling or pinching. 

Roles

Dominant and submissive

Master/Mistress and slave, one of the most common styles of roleplay, can be viewed as a subset of dominant and submissive. Other subtypes include ageplay (roleplaying a person of a different age), genderplay (roleplaying a different gender than their usual expression), and petplay (roleplaying an animal).

Top and Bottom

The top is the giving partner in the interaction, while the bottom is the receiving partner.

Sadist and Masochist

This pairing can be seen as a subset of top and bottom, focused on giving and receiving  intense physical sensations. 

Note that top, sadist and dominant roles don’t necessarily go together, nor do bottom, masochist and submissive roles. For example, a service top is a person who delivers intense sensation according to the instructions of the bottom. 

There are persistent but unfounded myths in BDSM culture that dominants or submissives must look or act a certain way, or that there is one authentic set of rules about how people in BDSM should interact. There is no such thing.