We explore two distinct yet related areas within blockchain technology. The first source, "Bridging On-Chain and Off-Chain Worlds: How Decentralized Oracles Work," focuses on decentralized oracles as essential middleware that connects blockchain networks with external, real-world data and systems. It highlights the "oracle problem" where blockchains are isolated from external information and details how decentralized oracle networks, like Chainlink, securely bridge this gap to enable diverse applications such as supply chain monitoring and decentralized finance. The second source, "RFC 9381: Verifiable Random Functions (VRFs)," is a technical specification detailing Verifiable Random Functions (VRFs), which are cryptographic tools for generating public-key-based, verifiable hash outputs. This document describes the security properties of VRFs, their construction using RSA and elliptic curves, and their application in preventing enumeration attacks on hash-based data structures. Together, these sources illustrate advanced cryptographic and connectivity solutions crucial for expanding the functionality, security, and real-world applicability of blockchain and smart contract systems.