Your v. You're

Your is the personal pronoun, meaning belonging to you.

You're is the contracted form of you are.

Here's a trick: don't use contractions in your essays (I can because this is a blog and I'm your teacher),  and you're should not present itself as a problem.

When I see you're for your or vice-versa, I don't actually faint from shock. I know it can happen to the best of us, because we often hear the words in our own minds when writing, and mixing one up with the other is a form of mispronunciation.  But you sure as hell need to know the difference when asked.