A service that publishes off-chain information onto the blockchain in a form smart contracts can consume: exchange rates, weather, sports results, real-world identity attestations. Without oracles, on-chain code only sees on-chain data; with them, it can react to the real world.
Because contracts trust the oracle's output blindly, oracle design matters: most production oracles aggregate multiple independent data sources to reduce the risk of a single bad feed corrupting downstream contracts.
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- Smart ContractSelf-executing code stored on a blockchain that automatically enforces and executes agreement terms when predefined conditions are met.View term
- DAppAn application whose core logic runs as on-chain code rather than on a single company's servers, so its rules keep working even if any one operator walks away.View term