I have a question on Session and Context scope but i really don't know what
it is.
 For a Page, Request and Session the object is created for each session. 
Now the question is when you get to Application scope is there a new object
created for each session? On page 123 you mention, as an example (in the
shopping cart), "If an application scope is specified then all users will
share the same cart" thus using the same object (am i right?). So does scope
relate to Context(for the server) and not the Session(for the client)?  Can
a client access an object throughout the whole application(mutiple
sessions)? Is this where the valueUnbound() comes in and stores the object
to some media?