4.10.11 - Homophone. One of two or more words, such as night and knight, that are pronounced the same but differ in meaning, origin and sometimes spelling.
Attention Tweeters, Facebookers, Texters and Bloggers...your is of or relating to you (possessive) and you're is a contraction of you are. Think of this quick sentence before pressing send...
You're certain this is your book??
They are homophones. Thank you for your support.