What is the difference between View and Portlet pages?
Views are related to how objects (data) are displayed in the GUI. Think of them as the "data-maintenance" screens.
Portlet pages contain portlets. A portlet may or may not be based on an object - often displaying read-only data based on SQL statements. Portlet pages can be added to the menu or can be "called" from other portlets. Think of them as the "data-display" screens.
Thanks! But the data-display can be done from Views with Category = "List Column". Is there any fundamental difference between Views with Category = "List Column" and Portlets?
Simple lists of the data items come as part of an object view... but portlets can be much more complicated than this simple view ; graphical views of data, views of data across multiple objects etc etc.
Yes you could easily build a portlet that looked and behaved like the list view, but with a portlet there is much _more_ functionality available.
Retrieving data ...