Plain English
An oracle is a service that brings off-chain data — prices, weather, sports scores — onto the blockchain. Smart contracts need oracles because they cannot read external data on their own.
How it actually works
Oracle networks like Chainlink aggregate price feeds from many sources, sign the data cryptographically, and post it on-chain. DeFi lending protocols, derivatives, and stablecoins all depend on oracle prices to function. A compromised oracle can drain a protocol — which is why oracle design is one of the most consequential security questions in DeFi.
What it means for you
When you supply collateral and borrow against it, the protocol’s oracle decides if your position gets liquidated. Oracle quality is your liquidation risk.
We teach how to read a protocol’s oracle dependencies, the difference between centralized and decentralized oracles, and the structural risk of relying on a single data source.
Educational content only. Not investment, tax, or legal advice.