The categories returned by the server, and the number of query results whose facet field matched each category.
The name of the field the facet was built on.
The number of query results that did not have a value for the facet field.
The arbitrary name associated with this facet.
The number of query results that had a value for the facet field, but whose value was not in any of the returned categories.
The number of query results that had a value for the facet field.