Acting similar to a moron, a youron is a person who incorrectly and carelessly types the word "your" when he or she should be writing, "you are" or "you're" to denote an action currently taking place. It is grammatically incorrect, ignorant, and frustrating.
Youron: If your going to the store, get me a pop!
Normal, polite person: If you are planning to go to the store later, could you please buy me a soda? Here's a few dollars.