Smart contracts are programs whose computation is run independently across a large number of distributed machines, with an output that is verified using a prede

Smart contracts are programs whose computation is run independently across a large number of distributed machines, with an output that is verified using a predetermined consensus mechanism. They are useful is situations where an actor would benefit from altering the result of the computation, or masking values. The primary use case that I've seen is for escrow payments with Ether, the Ethereum blockchain's native currency. They trade processing speed for finality and verification of results.