In addition to free text search Data Graphs provides search (filter) by facets. Facets are properties that have been defined for a Concept type. For example an aircraft might be associated with a manufacturer or a football players might be associated with a team. Faceted search allows you to combine a free text search with filtering based on a concepts properties.
Facets can be found on the left hand side of the search results screen. The default list of facets is always the Concept types. You can filter on any property you have defined as part of your schema. The additional facets can be found in the more facets dropdown.
When a facet is selected it filters the currently returned set of Concepts to only those that match that facet and any existing search criteria. Counts of matching Concepts are provided based on the what is currently returned with facets and search terms applied.
Faceting by Concept label is included for data quality purposes as it is useful to see where there is more than one Concept with the same label.
A property that is inherited from a parent type will work across all the Concept types that it inherit from it. For more information see Subclassing and inheritance.