I don't know in practical terms, but if it helps, S&M I believe refers to Sadism and Masochism (sado-masochist) which refers to someone who gets pleasure from inflicting pain (s) and from receiving pain (M). This pleasure can be sexual, so an S+M practioner derives sexual pleasure from inducing or receiving pain. This can involve bondage, whips, torture etc. Bondage is just a type of activity that can be used.

Essentially, BD and S&M can be practiced one without the other, but often they are intermixed in "scenes", so it tends to be lumped together into one term, "BDSM". BD and S&M can be kept separate depending on preference, however. Some people into S&M get off merely on the pain, without any of the bondage or power play. Conversely, there are people who like being tied up and/or dominated but don't like pain. People who are turned on by S&M might bring things like beating, cutting, or play piercing into the bedroom. BD people might incorporate spanking, but little else. I personally like to mix the two. Think of it as a bell curve with BD and S&M on opposite sites, and the highest portion of the curve being the 50-50 mixture of BDSM.

BDSM really stands for three separate things... B&D - Bondage & Discipline - being restrained in some way for being bad/good or for training and conditioning. This can be seen in what is called "pony play." One person is bound in (usually) leather, maybe a type of bit gag while being led around an "arena" forced to pick the feet up high or face a snap of the riding crop. D&S - Dominance & Submission - One (or more) person controlling another (or many.) This could be as simple as making someone push your cart while you do your shopping. It could be as deep as someone being complete control over another person in every possible way; when they eat, drink, use the restroom, sleep, what they wear... everything. (called 24/7 power exchange.) S&M - Sadism & Masochism - A sadist is a person who gets their kicks (no pun intended) by inflicting pain on someone, either physical or mental. This could be as simple as telling someone they are useless and do not deserve to be in your presence to applying cloth-pins to all parts of another's body and yanking them off one at a time. A Masochist is a person who gets their kicks by receiving physical or mental pain. Any thing from being humiliated (scolded)in public to being severely whipped or spanked. This is a deeper form of Dominance and Submission. Hope this helps you better understand what BDSM is all about. ~Jessie www.groups.yahoo.com/group/ClubLatexWI