Direct Answer: A relationship boundary is a limit you set around your own time, body, privacy, money, attention, or participation. It tells you what you will do when a situation crosses that limit. For example: 'If name-calling starts, I'll end the conversation and come back later.' The other person keeps their choices; you keep responsibility for your next step.
Relationship boundaries are the limits that help you decide what you will participate in and what you will do when something no longer works for you. A useful boundary is specific enough to act on. 'I need respect' is a value. 'If I'm called names, I'll end the conversation' is a boundary because the next step is yours.
Many relationship conflicts become easier to sort once you identify who controls the action. A request asks for cooperation. An agreement is chosen by both people. A boundary defines your own response. Control tries to remove the other person's choice. Classify the sentence before arguing about whether it sounds nice or strict.
Most relationship boundaries fall into a few recurring areas. The category helps you choose a response that fits the problem: a privacy boundary may change device access, while a time boundary may mean making your own plans instead of waiting.
Healthy boundaries are clear limits around your own participation, time, body, privacy, money, or attention. They leave the other person free to choose and give you a next step you can realistically take yourself.
'If name-calling starts, I'll end the conversation and come back when we are calmer.' The action belongs to you, it is connected to the situation, and you can follow through without forcing the other person to agree.
Check who controls the action. 'You cannot see your friends' tries to control the other person. 'If our plans keep changing without notice, I'll make my own plans' describes your response. Requests and shared agreements can still be useful, but they should allow a real choice.