Ughhhh! All caps rage. Am I exaggerating? No. No, I really don’t think so.
You’re is a contraction of two different words: you and are. You are. You’re. Eg: You’re illiterate!
Your is the possessive of you. It refers to something that is in the possession of the person in question/smth that a person has/etc. Eg: Your illiteracy grates me.
I know, I sound harsh, don’t I? I’m really not, I just can’t for the life of me understand how a person could confuse one for the other. It might be just me, but every time I see someone writing “your welcome” I feel like headdesking myself to death. Especially if that person is a native English speaker.
I’m not and even I know the difference.