Chainlink is a decentralized oracle network designed on the Ethereum blockchain. It is used to supply real-world (off-chain) data to the blockchain (on-chain) using smart contracts in a tamper-proof manner—the oracles within the Chainlink network leverage zero-knowledge proofs to provide data into blockchain networks.
Chainlink's native token, LINK, is an ERC677 token, an extension of the ERC-20 standard. It is used to pay node operators within the network as reimbursement for retrieving data from smart contracts. Node operators also make deposits in LINK tokens to contract creators. Several dApps, especially in the DeFi space, rely on Chainlink's services to access accurate real-world data, making it one of the leading blockchain oracle systems.
While some consider Chainlink to be a Layer-2 network, others believe it can be classified as a Layer-3 blockchain.
