This Diagram is from Addison Wesley’s “Eclipse Rich Client Platform 2nd Edition”. It demonstrates the relations between window, menu, perspective, views, etc.
In brief, window is the whole application view and it has one page. The page has its own editor and view instances, and uses the perspective to determine its layout. A view is used as a container to hold different kinds of widgets. Each widget can be a label, a button, a file chooser, etc.