modules in application - use multiple application-level windows?

I have an application that will have a number of different modules. And each of these modules will have different content(lists / forms). For example one module will be to modify users and another will be to modify orders. What is the best way to organise these ‘modules’ with Vaadin?

After reading the documentation it seems like what I need to do is create an application-level window for each module/page. This way they will continue to share the same session. Is this correct? Or is there another way I should be doing it? Another way would be to have just one Application and then display the ‘pages’ when the menu item is clicked. This seems kind of heavy to me and not very modular.

I apologise if this has been answered elsewhere. I have had a search around and could not find anything that answered my question.

EDIT : Have just found section 3.3 of the documentation. This explains well the concept and this tutorial is helping me alot. It still feels a bit weird to have everything tied so heavily to the base application class. I guess what I am after is some sort of event broadcast concept, like in Netbeans Platform, that will help keep the modules losely coupled. I will keep plugging away and I think this issue will resolve itself somehow as I get more in tune with Vaadin. So far I really like it!!

Me too, I would like to have opinions from the pros B) about this question.

Thank you, bye.