Blockchain & Infrastructure
Also: price oracle, data oracle
Oracle
An external data feed that brings off-chain information — prices, events, random numbers — onto the blockchain.
Oracles solve the problem that blockchains cannot natively access external data. A price oracle feeds real-world asset prices into smart contracts — DeFi lending protocols depend on accurate price feeds to calculate collateral ratios and trigger liquidations. Oracle manipulation is a common DeFi attack vector: if an attacker can distort a price feed, they can drain protocols that depend on it. Chainlink is the dominant decentralized oracle network; TWAP (time-weighted average price) feeds are used to reduce manipulation risk.