Apollo stacks are a powerful way to build and manage GraphQL APIs efficiently. By using Apollo Server and Apollo Client together, developers can streamline data fetching and state management. Apollo’s caching mechanism enhances performance by reducing unnecessary network requests. With Apollo, developers can easily integrate real-time functionality and subscriptions into their applications. The modular architecture of Apollo allows for flexibility and scalability in GraphQL development. Overall, Apollo stacks provide a comprehensive solution for building robust and responsive GraphQL APIs.