A reference layer is a layerA layer is a reference to a collection of geographic data that is used to access and display data. The data for layers are typically provided by the basemap layer service and data services.Learn more of information in a map that provides context to a location, such as labels for place-names, transportation routes, or other features of reference. Typically a reference layer is part of a basemapA basemap layer is the layer in a map or scene that displays basemap data. The data source for a basemap layer is typically a basemap service.Learn more.