## 🍣 oracles
* Oracles provide a trustless way of getting extrinsic (off-chain) information.
* They provide the some key functions such as collect data from an off-chain source, transfer the data on-chain with a signed message, and make the data available by putting it in a smart contract’s storage.
### chainLlink
A decentralized oracle network consisting of three key smart contracts:
* a reputation contract: keep track of data providers' performance.
* an order-matching contract: selects bids from oracles using the reputation contract.
* an aggregation contract—and an off-chain registry of data providers.
One of the main challenges with such a decentralized approach is the formulation of the aggregation function.
ChainLink proposes calculating a weighted response, allowing a validity score to be reported for each oracle response.