Power exchange
The consensual handing of control from one person to another in play or a relationship; rope teachers describe being tied as an exchange of power that rests on trust.
Power exchange means one person consensually giving another control, for a scene or within a relationship. Wikipedia’s Glossary of BDSM treats D/s as play or relationships in which power is handed over on a psychological level. Anatomie Studio calls shibari fundamentally an exchange of power, since letting someone tie you takes considerable trust, and points to Betty Martin’s Wheel of Consent as a way to examine power in any relationship and make sure what is exchanged is consensual. Rope 365 (Ebi McKnotty) adds a caution: dynamics such as D/s, teacher and student, or money between partners can make it harder for someone to speak up, so confirming consent takes extra care.