Visual InterDev
A directory that appears to be a subfolder to the root of the server but may actually exist in a subfolder that is any number of levels under the root or elsewhere on the network.
The name of the virtual root can be the same as the actual subfolder or may be an alias specified on the server. For example, in the URL http:/MyWebServer/MyWebApplication, "MyWebApplication" specifies a virtual root on the Web Server, "MyWebServer." The actual folder for MyWebApplication maybe file:\\MyWebServer\Default Web Site\MyWebApp.