Mule can run web applications through its embedded Jetty container. This allows a web application deployed in Mule to interact with Mule flows. For example, a JSP page could accept user input and a Mule flow could expose a web service to handle that data in the backend by storing it to a database. When the data is inserted, the web service returns a response back to the JSP page. So the web application and Mule flows are able to seamlessly pass data between each other with Mule hosting the web application.