Trying to wrap my head around Diez's MVC page model...

I'm struggling to complete the picture using Diez's page model.  

I feel like I'm starting to understand the MVC model a bit.  When
looking at the example pages in the project I see stuff that
looks to me like Controller (notifyListeners->handleEvent) and 
View (render->handleViewEvent), but nothing that really jumps 
out at me as a Model...  By Model I mean taking input and 
using it to challenge a datasource (file, database, calculation, 
system variable, etc) to produce a result which gets fed back 
to the view...

It could just be that that all the examples in the Models directory
(ChildFormMap, ExampleFormMap, ParentFormMap) define only 
FormElements is what's confusing me. 

Do I just define some classes in the Models directory and call 
them or is there something more to it?  

-Garth