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.