Smart Contracts [↗] on the Blockchains [↗] are usually set up to execute an action based on events or changes in the state of something. Getting information from the blockchain they run on is straightforward.However, if a contract needs information about the real world, things become tricky.
Smart contracts must rely on third-party services to provide them with reliable real-world information, for example, the weather in a specific area or the outcome of an election.
These third parties might also provide smart contracts with ways to interact with the real world or with other services, such as data stores.
These services are known as Oracles [↗]
One of the core principles that these Oracles must adhere to is ensuring that the data source is trustworthy. One way they achieve this is by drawing consensus from data collected across multiple sources or parties whenever possible. Where that is not possible, an agreed-upon reliable source is used instead.
The process of integrating these oracles into a blockchain or, more specifically, into a smart contract is known as chainlinking.
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