A stateful web application is a type of application that maintains the state of user interactions across multiple requests. This means that the application remembers information about the user’s session, such as login status or items in a shopping cart, allowing for a more personalized experience. In contrast to stateless web applications, which treat each request as an independent transaction, stateful applications rely on mechanisms like cookies or sessions to store user data. This enables features like user authentication and data persistence, making them essential for applications like e-commerce platforms and social media sites.