Decentralized finance (commonly referred to as DeFi) is a blockchain-based form of finance that does not rely on central financial intermediaries such as brokerages, exchanges, or banks to offer traditional financial instruments, and instead utilizes smart contracts on blockchains, the most common being Ethereum.
More specifically, the term Decentralized Finance may refer to a movement that aims to create an open-source, permissionless, and transparent financial service ecosystem that is available to everyone and operates without any central authority.