DeFi stands for Decentralized Finance. DeFi covers a wide range of topics, but in general it’s the recreation of modern financial tools and concepts on Ethereum and other blockchains. It’s decentralized because it removes intermediaries like banks and other financial institutions. Anyone can access them regardless of who they are or where they live. All you need is a wallet and some funds to get started.
To learn more you can read our blog: What is DeFi and Why Do We Need It?