Searched terms referenced?

[JAB Creations]

I have seen a tool that lets you look up all searched terms using words and how many times that word/phrase/etc was searched for on google. For example...

blue carpet 845
sky blue carpet 54

You'd type something in like carpet and it would show related searchs that ALREADY have been searched for allowing you to see what people are actually searching for beyond what comes to what access logs/etc you have at your own end.

Does anyone know what tool this is or at least what "type" of tool this would be referenced as?