ok, we actually beleive there is more than just heaven and heck. we actually beleive there are 3 kingdoms, and then what is called "outer darkness" which is like heck.  
 
CELESTIAL KINGDOM: the first and greatest kingdom is the celestial kingdom. (kind of like the sun kingdom.) it is the greatest place ever, and only if you are a very good, and of are the right faith, (mormon) and have repented of ALL of your sins can you get there. (we also beleive that the celestial kingdom is broken in too ANOTHER 3 parts, and you have to be married in the temple to get to the highest of those 3 parts.)  
 
TERESTIAL KINGDOM: the second is the terestial kingdom. (kind of like the moon kingdom) you do not have to be mormon to get there. if you were a good, wonderful person, but maybe didn't repent of all your sins or something, you get to go to the terestial kingdom. the terestial kingdom is just about like earth. 
 
TELESTIAL KINGDOM: the telestial kingdom is the last kingdom. (it is like the star kingdom) it is worse than earth, but you dont deserve to go to heck!  
 
OUTER DARKNESS: another word for heck. (pretty much self-explanitory)