Decentralized finance (DeFi) is a promising application of blockchain technology that enables users to interact with financial products and services without the need for intermediaries such as banks or financial institutions. Ethereum is the most widely used platform for building DeFi protocols, providing a secure and decentralized infrastructure. DeFi protocols built on Ethereum offer a range of financial services, including lending, borrowing, derivatives, and asset management. This article explores the role of DeFi in the Ethereum ecosystem and its potential as an investment opportunity.