Block Chains - A New Type of Data Base

There's not yet a great case for block chains to be used in every situation. Nobody owns the block chains, at least in their idealized state. So i'm on the block chain. You have smart contract. But what is it? What is a smart contract? I don't very good at reading them or writing them, buti know what one is. And so before people goothingit and building everything on wetthr and block chains, we're not even close to that at this point.