In D/s, one takes pleasure or erotic enjoyment out of either dominating or being dominated. Those who take the controlling position are commonly called Doms (male) or Dommes (female), those who take the controlled position are called subs or submissives (male or female). Submissives generally outnumber Dominants in the general population, with male subs outnumbering Dommes by the widest margin, often three to one or more. "Dominatrix" is a term usually reserved for a female Professional dominant who dominates others for pay. It should be noted that a Dominatrix is not a prostitute, and no sexual services are provided.

There can be any number of partners in a D/s relationship, with one Dominant sometimes having several subs, who may in turn dominate others. Relationships with multiple Dominants and a single submissive are rarer but still possible. The most common combination is a pair with a Dominant and submissive, often in an ongoing committed relationship. Romantic love is not necessarily a feature in D/s, but is common; partners can be very much in love or have no romantic relationship at all.

It should be borne in mind that Domination & submission is about an interaction between people. That someone chooses to dominate someone in a personal relationship does not necessarily imply that they are generally dominant in the rest of their lives or, if they are, that it is noticeable. Likewise, someone who is submissive in a relationship will not necessarily be generally submissive. For some submissives, it can take a great inner strength to go against social pressure and allow the dominant partner to make decisions on their life.

Variation in BDSM is extensive and activities take many forms, and may include servitude, verbal abuse, humiliation, consensual slavery and sexual slavery, and may be combined with other forms of BDSM in myriad combinations. Bootblacking is another form of D/s, where one person polishes and lavishes attention on another's footwear as an expression of submission. D/s participants often refer to their activity as "play", with an individual play session called a "scene".

Some D/s relationships are sexual, others completely chaste. Fantasy role play can also be a part, with partners taking classic dominant/submissive roles such as teacher/student, police officer/suspect or parent/child. Animal Play, where one partner takes the role of owner/caretaker and the other takes the part of a pet or animal, is also considered D/s play. Some people maintain a special room or area, called a dungeon, which contains special equipment (E.g. shackles, handcuffs, whips, queening stool, spanking bench, etc.) used for play scenes. Or, they may visit a BDSM club that maintains such facilities.

Consent is a vital element in all psychological play, and consent can be granted in many ways. Some employ a written form known as a "Dungeon negotiation form", for others a simple verbal commitment is sufficient. Consent can be limited both in duration and content. It's not unusual to grant consent only for an hour or for a evening; such arrangements are often termed New Style as opposed to more lengthy Old Style relationships. Some "contracts" can get quite detailed, especially if a scene is to last a weekend or more.