Discipline is a common element in BDSM play, and is even sometimes represented by the letter "D" in this acronym. Discipline refers to the practice of training a submissive to obey a dominant and follow certain rules. It is most common during submissive or slave training, but discipline is also present in all aspects of the relationship between a dominant and submissive. Although punishment can go hand in hand with discipline, it typically focuses more on helping a submissive learn what is expected of them and how to act accordingly. For instance, if a submissive makes an honest mistake, it is the dominant's responsibility to discipline them by showing them the proper way to do something. Punishment usually occurs only when a submissive willfully breaks a rule.
It is important to note that those in the BDSM community view the ability to submit as a source of empowerment for the submissive.
More About Discipline
Although punishment often goes hand in hand with discipline, it is not the only aspect of it. For example, when a submissive does something in such a way that it does not please a dominant, the submissive will usually need to be disciplined. This usually involves the dominant explaining what they disliked as well as teaching the submissive how to do it properly. In some cases, a punishment may also be used to help a submissive learn a particular lesson better. However, the punishment should always be related to the infraction. For example, a proper punishment for speaking out of turn may be forbidding speaking or enforcing silence with a gag for a certain amount of time.