As Bitcoin was the first cryptocurrency, it was also the first example of simple smart contracts. However, due to its nature, bitcoin is used only for money transfer purposes.

Ethereum smart contracts are leaving bitcoin at this point. By using the Ethereum code structure, developers can develop smart contracts that can serve many different purposes.

Any user can create a smart contract using ethereum infrastructure and put it into use. (In early 2018, there were reports that the ethereum-like smart contract period will begin in the bitcoin blockchain, but we can say that it is still in the trial process.)

Ethereum developer Vitalik Buterin explains how smart contracts work at a blockchain summit: "Contracts are converted to computer language and recorded in blocks. Contracts copied into distributed ledgers keep parties 100 percent anonymous. ..) stand by. When the time comes, it takes action to fulfill the transaction and if the necessary conditions are met, the transaction is successfully completed or canceled before completion.
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