The research team at CoinGecko, one of the most respected data providers in the cryptocurrency space, wrote this practical beginner's guide to decentralized finance as a resource for the rapidly growing number of people seeking to understand and participate in DeFi protocols without the technical background typically required to navigate academic or developer-focused documentation. The book covers the foundational infrastructure of DeFi — the Ethereum network, wallets, gas fees, and smart contracts — before systematically walking through each major DeFi protocol category with practical guidance on how to actually use them. Chapters cover decentralized exchanges and how to trade on Uniswap and similar protocols, lending and borrowing on Compound and Aave, yield farming strategies and the risks of chasing high APY, stablecoin mechanics and the differences between fiat-backed and algorithmic stablecoins, and the emerging ecosystem of DeFi derivatives and insurance protocols. The book is notably candid about the risks involved: smart contract exploits, impermanent loss, liquidation risk, and the significant regulatory uncertainty surrounding DeFi activities. Updated editions have expanded coverage to include layer-2 networks that dramatically reduce the transaction costs that made many DeFi strategies economically unviable for smaller participants on the Ethereum mainnet. While some specific protocol details require updating as the space evolves rapidly, the conceptual framework and introductory guidance remain among the clearest available for DeFi newcomers.