Blockchain and oracles are critical components in developing decentralized applications, both leveraging cryptography, decentralized consensus, and crypto-economic incentives for security. While blockchain provides an immutable backend infrastructure for storing data and executing tamper-proof computations, oracles extend the functionality of smart contracts by connecting them to off-chain data and computation resources. This combination creates hybrid smart contracts that maintain blockchain’s security while enhancing connectivity, scalability, privacy, and fairness. The article explores the goals and infrastructures of blockchain and oracles, highlighting their differences and synergies. Blockchains are designed to maintain a distributed ledger of digital assets, utilizing a network of miners/validators for transaction verification, while oracles focus on verifying off-chain data and events to produce authoritative facts. Despite differences, both utilize open-source code, decentralized networks, cryptographic signatures, and economic incentives for security. The integration of blockchain’s secure, standardized computing with oracle's flexible and scalable data processing capabilities enables the development of advanced hybrid smart contracts, facilitating decentralized applications that require high-throughput computation and external connectivity.