What is the half-blood prince in Harry Potter?

I watched the movie but didn't read the book but all i know is that Snape is the half blood prince... all i know is that the sorcerer's stone is some stone that makes u powerful or whatever, and the chamber of secrets is a chamber created by salazar slytherin, the prisoner of azkaban which is a wizard named sirius black who ppl thought he killed 13 ppl which one curse and escaped azkaban after 12 long years, the goblet of fire which is the fire that tells who can enter the triwizard tournament, the order of the phoenix which is a secret society by dumbledore against voldemort, and what the hell is the half blood prince? a half blood that can destroy the world and is the most half blood ever? i understand what it means 0%ly. what is it? anybody tell me?