The term bottom is often used to describe an individual who plays a subservient or receiving role for kinky activities in BDSM. A submissive is not necessarily also a bottom.
A bottom can be its own identity to itself. Not all submissives will bottom. Some people are only submissives or only bottoms.
A bottom's degree of submission can vary depending on their desires and the agreements made with the top. This may simply include receiving a single, negotiated BDSM activity, and it may include agreements to serve the top for drawn-out scenes or relationships.
Tops and bottoms may not be in a power exchange relationship at all. The term "top" or "bottom" may simply be used to designate who is doing - or receiving - an activity. No power exchange relationship is required for that.
