Chainlink is a decentralized oracle network that allows blockchain smart contracts to connect to real-world data including objects, market prices, weather, and APIs. It acts as a secure bridge, enabling smart contracts to work with information outside the blockchain  something they can’t accomplish on their own.

Chainlink uses independent node operators, known as oracles, to secure external data, which they ensure delivery on-chain without sacrifices to reliability and tamper-resistance. This bypasses the “oracle problem” by eliminating reliance on one particular data stream.

Founded by Sergey Nazarov and Steve Ellis in 2019, Chainlink is now a necessity for DeFi and most Web3 applications. Developers use it for decentralized price feeds, randomness for games, automated contract execution, and cross-chain communication  all while securing tens of billions of dollars in the process.