A decentralized protocol is a set of rules encoded in open-source software, executed across a distributed network without central control. These protocols define how participants interact, validate transactions, and reach consensus. Examples include Bitcoin, Ethereum, IPFS, and Whisper. They enable trustless peer-to-peer applications—money transfers, data storage, communication, governance—without intermediaries. Transparency and open governance ensure resiliency and auditability. Decentralized protocols underpin DeFi, DAOs, NFT marketplaces, and Web3 services. Their design balances decentralization, security, and scalability, allowing innovation through composability and permissionless participation in global ecosystems.