Express is a lightweight and adaptable web application framework for Node.js, designed to offer a comprehensive array of features suitable for both web and mobile applications. It equips developers with a wide range of HTTP utility methods and middleware, facilitating the swift creation of powerful APIs. By providing only a minimal layer of essential web application functionalities, Express ensures that the core features of Node.js remain accessible and transparent to developers. Notably, it does not impose any database requirements, allowing developers the flexibility to connect with virtually any database through third-party Node modules. Additionally, a 404 response in Express is intentionally not treated as an error; rather, it signifies that all middleware functions and routes have been executed without yielding a response. This unique handling of 404 statuses underlines Express's philosophy of clarity and simplicity in web application development. By putting the focus on essential features and allowing developers to build upon them, Express empowers users to create tailored solutions that meet their specific needs.