Boundaries involve setting rules that make it clear how you want to be treated.
Sometimes, this means saying something like, “No, I won’t loan you my car.” Other boundaries involve telling someone what you expect like, “I expect you to call before showing up at my house.”
It’s important to announce your boundaries to other people. You might say, “Please don’t ask about my health issues in front of other people.”
At times, however, it’s best to show what your boundaries are with your behavior. If you’re at a dinner party where people start drinking heavily and you’re uncomfortable, you might find it’s best to leave without offering an explanation about why.
Setting boundaries can feel uncomfortable at first if you aren’t used to setting them. But establishing clear boundaries shows you have respect for yourself, and it can be the key to establishing healthy relationships with other people. 
There are a lot of misconceptions about boundaries. These misconceptions often spread quickly on social media and cause many people to misunderstand how to set boundaries in a healthy way.