Chainlink has emerged as one of the best-performing altcoins in 2020. It is a decentralized oracle network that provides off-chain data to blockchain systems, acting as a bridge between the real world and blockchain environments. By connecting smart contracts to external data sources, Chainlink solves the problem of relying on centralized data. It also aims to address blockchain interoperability by acting as a protocol to connect different blockchains. The Chainlink token, LINK, serves two functions: it is used to pay node operators for data services and as collateral to ensure uptime for the nodes.