Exhibit/Lenses Views and Facets
Views are ways of looking at collections of items.
Lenses are ways of formatting individual items.
Views will show collections of items, often by invoking lenses to show each item in the collection.
Facets are the properties of items which you can expose for filtering/searching on an exhibit.
Views and Facets can be restricted to show objects of a certain type by using "Collections" (See http://simile.mit.edu/wiki/Exhibit/2.0/Collections )