Glossary
Price Feed
An on-chain stream of asset prices published by an oracle, used by DeFi protocols to value collateral, trigger liquidations, and settle derivatives.
A price feed is the most-used kind of oracle output. The oracle aggregates prices from many off-chain sources, applies medianization or robust averaging, and publishes the result to a contract that DeFi protocols read.
Feeds vary in update cadence (heartbeat + deviation triggers), staleness handling, manipulation resistance, and trust model. A manipulated or stale price feed is the single most common cause of DeFi exploits — protocols that combine multiple independent feeds or use TWAPs on top are noticeably more robust.