Understanding b|D|s|m More

Sadism is the sexual pleasure or gratification in the infliction of pain and suffering upon another person.

The counterpart of sadism is masochism, the sexual pleasure or gratification of having pain or suffering inflicted upon the self, often consisting of sexual fantasies or urges for being beaten, humiliated, bound, tortured, or otherwise made to suffer, either as an enhancement to or a substitute for sexual pleasure.

Sadists enjoy inflicting pain whether or not it is sexual in nature.
Masochists enjoy receiving pain, which, again, may or may not be sexual.

Dominance and submission (D/s) is a way of looking the the sadistic-masochistic distinction, a power dynamic rather than a set of acts.

Not all masochists are submissive, and not all submissives enjoy pain.
Not all sadists are dominant, and not all who enjoy dominating others are sadists.

There is frequently a strong emotional aspect to the sexual desires, taking the form of a need for domination (to control another) or submission (the desire or to be controlled) as opposed to a simple desire for pain (which is technically known as algolagnia).
The words sadistic and masochistic are now commonly used to describe personality traits in an emotional, rather than sexual sense. Sadism involves causing physical or psychological pain or suffering to another person.

As long as it occurs with a consenting partner, it can be argued that sexual sadism is not considered to be a psychological disorder.

It is certainly considered a [ disorder ] when it [ causes unhappiness ] to the person with it, [ causes problems ] with work, social setting, or family, or when there is [ potential danger ] to another individual.

Like some masochists, some sadists require the pain or humiliation in order to function sexually. Others may engage in more typical sexual activities at some times and sadistic activities at other times.
Sadists often seek out masochists as sexual partners. The sexual arousal in sadism is directly related to the suffering of the other person.
Some acts involve actual physical violence. Other acts involve domination, such as making the other person crawl or keeping him or her in a cage.

Sadism and masochism, often interrelated (one person obtaining sadistic pleasure by inflicting pain or suffering on another person who thereby obtains masochistic pleasure), are collectively known as S&M or sadomasochism.

The term BDSM describes the quite common activities between consenting adults that contain sadistic & masochistic elements. Many behaviors such as erotic spanking, tickling and love-bites that many people think of only as “rough” sex also contain elements of sado-masochism.