A core feature of the Ethereum blockchain and NFTs are Smart Contracts. They are just typical legal contracts, but they are codified into the blockchain. Main purpose behind the smart contract is to permit trusted transactions and agreements to be carried out among disparate, anonymous parties without the need for central authority, legal system, or external enforcement mechanism. The code and the agreements contained therein exist across a distributed, decentralized blockchain network, the code also controls the execution of the contract.