Oracles
From Chainlink Community Wiki
“A blockchain oracle is secure middleware that facilitates communication between blockchains and any off-chain system, including data providers, web APIs, enterprise backends, cloud providers, IoT devices, e-signatures, payment systems, other blockchains, and more.” - (Source: What is the Blockchain Oracle Problem? (https://blog.chain.link/what-is-the-blockchain-oracle-problem/))
Oracles maintain a critical role in crypto infrastructure as a means of connecting smart contracts to off-chain data
Oracles are the entities that connect blockchains to real-world data and existing systems, and provide critical infrastructure for establishing a unified, interoperable Web3 ecosystem.
Chainlink oracle networks not only feed financial market data on-chain to power DeFi applications, but they also provide a wide range of secure off-chain computations such as verifiable randomness and decentralized execution to enable dynamic NFTs and highly automated dApps. Moreover, with the development of the Cross-Chain Interoperability Protocol (CCIP), oracle networks will help enable the fast-growing ecosystem of different blockchains and layer-2 scaling solutions to securely communicate with one another.[1]