MapKit and GeoToolbox framework patterns for location-based features. Covers PlaceDescriptor (standardized place representation across mapping services), PlaceRepresentation (.coordinate, .address), SupportingPlaceRepresentation for third-party service IDs (Google Places, Here, Foursquare), MKMapItem ↔ PlaceDescriptor conversion, Map view with annotations and overlays, geocoding, local search, and place sharing. Use when building location features, implementing maps, working with place data, or integrating with third-party mapping services.