Built in web server?

I know this is a part of WebStorm, but I see no discussion of the built in web server as part of IDEA. That said, it's clearly there, because when I go to http://localhost:63342/, a 404 page is returned that includes the text "IntelliJ IDEA 12.1.4".

I've tried to have the server work with a web module that I have running, but I can't figure out the path where the file might be, and the internal server offers no information about where that might be.

Is there any help content for this built-in web server?