BDSM is a term which describes a number of related patterns of human sexual behavior. The major subgroupings are described in the abbreviation “BDSM” itselfOther interesting facts:

A dominant person enjoys controlling a submissive person. Reasons for this are said to include demonstrating skill and power, having ownership of another person, and being the object of affection and devotion. Domination may be the fashion in which the dominant feels most comfortable expressing and/or receiving affection. Service-oriented dominants would add that it is obviously useful to have the resources and abilities of another human at their disposal. In addition, many fantasies involve the reversal of traditional roles or contraints. So men or women who traditionally have powerful roles in contemporary culture may wish to experience submissive roles, while others who normally are responsible for enforcing traditional morality, may wish to experience situations where such limitations do not exist.

Of course, other known possible motives remain to be considered, including pleasure taken not only in sheer power, but in the suffering of others, which is called sadism, thrill seeking in risk taking, and outright self destructiveness. That is why many in the BDSM community are concerned with establishing the motivations of those involved in an encounter and advise caution in making BDSM connections.

Submissive behaviour
A submissive person is one who, of their own free will, seeks to submit to another. Submissives vary in how seriously they take their position, training, and situation. Motivations for engaging in submissive behaviour may include relief from responsibility, being the object of attention and affection, gaining a sense of security, showing off endurance, and working through issues of shame. Others simply enjoy a “natural” feeling when they are in the presence of their partner. What are known as service-oriented submissives may also have a deep seated desire to be “of use”. Submissives also vary in the extent to which they engage in play, in how often they play, and even in whether they consider their role “play” at all.

Tops and bottoms
In BDSM, a top is a partner who takes the role of giver in such acts as bondage, flogging, humiliation, or servitude. The top performs acts such as these upon the bottom, who is the person receiving for the duration of a scene. Although it is easy to assume that a top is dominant and a bottom is submissive, it is not necessarily so.

The top is sometimes the partner who is following instructions, i.e., he tops when, and in the manner, requested by the bottom. A person who applies sensation or control to a bottom, but does so to the bottom’s explicit instruction is a service top. Contrast the service top with the pure dominant, who might give orders to a submissive, or otherwise employ physical or psychological techniques of control, but might instruct the submissive to perform the act on him or her.

The same goes for bottoms and submissives. At one end of the continuum is a submissive who enjoys taking orders from a dominant but does not receive any physical stimulation. At the other is a bottom who enjoys the intense physical and psychological stimulation but does not submit to the person delivering them. It should be noted that the bottom is most often the partner who is giving instructions—the top typically tops when, and in the manner, requested by the bottom. However, there is a purist school of BDSM, for whom such “topping from the bottom” is incompatible with the retention of high ethical standards in the relationships wherein BDSM is practiced.

Within a sadomasochisic context, submissive is often considered synonymous with bottom. Others opine that a “submissive” is specifically pursuing a dominant/submissive power-exchange as a key element, whereas a “bottom” may or may not be interested (or even willing) to engage in that exchange. For the latter, some have proposed the “pitcher” and “catcher” as more neutral terminology, with the “pitcher” delivering the sensation, the instruction, etc; and the “catcher” receiving what is “pitched.”

Switching
Some practitioners of BDSM enjoy switching—that is, playing both dominant and submissive roles, either during a single scene or taking on different roles at different occasions with different partners. A switch will be the top on some occasions and the bottom on other occasions. A switch may be in a relationship with someone of the same primary orientation (two dominants, say), so switching provides each partner with an opportunity to realize his or her unsatisfied BDSM needs with others. Some individuals may switch, but may not identify as a switch because they do so infrequently or only under certain circumstances. Sometimes individuals switch in just physical roles (top and bottom), and sometimes individuals may switch completely in emotional roles (dominant and submissive) as well.

1) BDSM may or may not involve sex of any kind.
2) BDSM may or may not involve sexual roleplaying.
3) How dominant or submissive a person may be in their regular life does not necessarily indicate which role they will play in a scene.
4) Some BDSM players are polyamorous or sexually monogamous but engage in non-sexual play with others.
5) A couple may engage in BDSM sexuality with an otherwise non-D/s relationship dynamic. When there is abuse in the relationship, the dominant is not necessarily the abusive partner.