A development server is a localized environment that mimics the production server, allowing developers to test and refine code changes in real-time. In the context of Python, [[Choosing a Web Framework]] like [[Django]] utilize development servers to streamline web development by offering immediate feedback, as opposed to traditional deployment which can be time-consuming. Similarly, in the realm of frontend, [[React.js]] uses a development server to render UI components dynamically, ensuring seamless integration with backend systems like Django.