Express.js is a robust Node.js web application framework that provides a simple yet powerful API for building web and mobile applications. It offers various features and middleware that make it easy to handle HTTP requests, routing, and middleware functions.
Next.js is a popular open-source React framework for building server-side rendered, production ready web applications. It provides out-of-the-box performance optimizations, such as automatic code splitting and server-side rendering, and supports dynamic data fetching with minimal configuration.