Most blockchain networks use smart contracts, which are special programmable agreements that are verified in the blockchain. These crypto contracts have unique wallets that automatically process the transfer of data, provided that certain predetermined conditions are met. A transaction that is outside the blockchain cannot be performed without an oracle telling/notifying the smart contract how the data is to be handled. It is important to have unbiased, independent and transparent sources of data in order to make blockchains work in the real world, which is possible through Chainlink.