They both sound the same. But when written, they could spell the difference between a well-written sentence and a grammar disaster. So here's a quick guide for when you should use your and you're.
YOUR implies that you own something.
YOUR, in this case, is referring to YOUR disgusting furbaby and YOUR car.
YOU'RE is a contraction of YOU ARE.
This translates to "If you are not going to get the damn cat to quit washing his ass in public, you are going to see me swinging away at a bat while I'm inebriated out of my mind!"
So kids, remember: it's important to know the difference between YOUR and YOU'RE!