A DeFi aggregator is a platform that collects and consolidates DeFi opportunities from multiple decentralized protocols, making it easier for users to access various DeFi services. These aggregators allow users to compare yield farming, liquidity pools, and lending protocols, optimizing returns. They streamline the decentralized experience by providing users with the best rates across different platforms, ensuring more efficient asset management, reduced gas fees, and broader access to decentralized finance applications.