This is an attempt to define BDSM briefly using book sources and sites around the web. It is accepted here that there is a nuance to BDSM and that methods and techniques are individual to the participants. It is also accepted that nobody will necessarily just fall into one category, many spanning all aspects of the definition. But the point being made here is that there is basic criteria and to be part of BDSM would require participating in at least one aspect of the definition.
The origins of the term BDSM can be found in the Glossary on this site
The Play
B&D stands for Bondage and Discipline but the term is used more commonly to describe the people who play together as-and-when but have no power exchange in between sessions.
B&Ders rely heavily on safewords to control play. The Top is empowered to dominate by the bottom's consent. This consent can be withdrawn at any time during play and that withdrawal will be respected by the Top.
The term B&D most often covers the club scene but also takes in the itinerant ropers who enjoy doing bondage and suspension, those who specialise in shibari and disciplinarians who help to modify behaviour like tardiness or quitting smoking.
B&Ders often enjoy role play scenarios such as headmaster/pupil, master/slave, medico/patient.
Many are into B&D just for the kink and the fun and can take it or leave it on a whim. Others may actually be need-driven.
Recent changes have seen B&D referred to as SM or S/M (not to be confused with S&M, see The Pain paragraph below).
In B&D the players are usually known as Tops and bottoms and quite often enjoy switching roles.
The Power
D&s stands for Domination and submission in a total power exchange (TPE) relationship. It is sometimes referred to as M/s.
D&s relationships are generally long term commitments where the power exchange is accepted as being there 24/7/365. Submission/consent is given once on the outset of the relationship and is present throughout. To withdraw consent would break the submission and end the D&s relationship. D&s therefore relies heavily on trust, honesty, love and care from both sides.
People have often dismissed the TPE as being unworkable, believing that it means the sub is left naked and in chains, all day every day, in their Dominant's service but this is some fantasy perception and not reality at all. Although D&s submissives live in service to their Master/Mistress, the personal dynamics between them do not alter their social or business personnae and both partners are as adept as anyone else to lead mainstream public lives
Another misconception is that D&s describes the sex games of being passive or dominant, either privately or in swingers groups, to enhance love-making or raw sex. If the TPE is not present throughout all aspects of the relationship then it is not D&s.
D&s and M/s are need-driven, that is to say that something deep in the core of the person forces them to seek out this type of relationship. It is not a game or a kink.
Partners in this arena are most often known as Master/Mistress and sub.
The Pain
S&M stands for sadism and masochism and covers the ones who need to give pain and the ones who need to take pain. These can run in parallel quite neatly with either of the above definitions.
Generally S&Mers need to get to the point of what would be regarded as non-consensuality. To the tears and beyond. To the outsider this is often seen as abusive. However, since the partner has consented to stay in the presence of the sadist it falls into the realms of consensual non-consensuality.
As with D&s, S&M is need-driven and taken very seriously. If the needs are not met they manifest in bad health and social dysfunction.
Because some people like the concept of the darkness and awe of S&M but have no drive to push limits, seeing it as abusive or mentally unstable, recent changes have produced the term SM or S/M rather than S&M. This describes the people who do caning and flogging for mutual erotic pleasure with safewords as in B&D (see The Play paragraph above) whilst keeping themselves safely seperate from the "hard core" sadists and masochists who are out to push beyond limits to get where they need to be.
As with B&D many do this pseudo S&M for fun and kink and can walk away from it whenever they get bored with it all.
S&M activities tend to be illegal ones, falling under the laws of ABH and GBH and consenting to them will not be accepted as a defence in a court. S&Mers rarely participate in their activities in the public arena unless in small private and exclusive groups.
SM and S/M are the play version and activities there are rarely seen as illegal unless the safeword is abused.
The participants of S&M can be Top, bottom, switch, Master/Mistress or sub depending upon the type of relationship they have.
Sources :
Deviant's Dictionary - Designed, edited and maintained by Dirk - website
Different Loving - Brame, Brame and Jacobs - book
Screw the Roses, Send Me the Thorns - Miller and Devon - book
Sex Maniacs Ball - Book of Delights - website
Wikipedia - website