The term virtual host refers to the practice of maintaining more than one server on one machine, as differentiated by their apparent hostname. For example, it is often desirable for companies sharing a Web server to have their own domains, with Web servers accessible as www.company1.com and www.company2.com, without requiring the user to know any extra path information.
Geronimo provides different distribution with Web Contaniner such as Tomcat and Jetty, you may look into the following pages to learn how to configure virtual host together with Geronimo.