Oracles are third-party information service providers who send real-world data to blockchain protocols (often to a smart contract or numerous smart contracts). Oracles significantly increase the power of blockchain network protocols because they can exponentially secure, verify, and strengthen the validity of the data that a blockchain network receives and uses (because blockchains and smart contracts are often closed systems). Oracles can be decentralized, relying on multiple data sets, or centralized, relying on a single entity. One of the primary applications of blockchain-based oracles at the moment is to provide the price and data feeds required for the trustless execution of smart contracts used by financial mechanisms in the DeFi sector.