Next.js is a React framework that enables functionality such as server-side rendering and generating static websites for React-based web applications. It provides a zero-configuration build tool for React and includes many optimizations out of the box, making it ideal for production applications.
React is a declarative, efficient, and flexible JavaScript library for building user interfaces. Developed by Meta (formerly Facebook), it lets you compose complex UIs from small and isolated pieces of code called components. React's virtual DOM and component-based architecture make it ideal for building modern web applications.