DeFi, or Decentralized Finance, refers to a broad range of financial services - such as lending, borrowing, trading, and investing - built on blockchain technology. Unlike traditional finance, DeFi platforms operate without banks or central authorities, using smart contracts to automate transactions and manage assets. This allows users to interact directly with financial products in a transparent, open, and often global environment. DeFi aims to make financial services more accessible, efficient, and resistant to censorship or single points of failure.