Someone who is "stubborn" won't change their mind. Once they've made a decision, they will continue with that decision even if you give them a lot of good reasons to change. Here's how you use the word "stubborn":

Don't be so stubborn!

Being "stubborn" is usually a bad quality.

You can talk about this quality with the word "stubbornness":

Stubbornness is not something to be proud of.