55154635_ual_Globe____ArcGIS_Comparison__ArcGIS_KML_Layer_Functionality
[KML Feature] Network Links
Network links allow KML content to be fetched dynamically from a KML server. Network links can be defined with automatic refresh properties, allowing the content to be fetched at specific time intervals or whenever the view extent is changed. While automatic refresh of network links (usually by a timer) is not supported by ArcGIS, you can manually refresh the KML layer at any time in order to get the latest content.
USGS InfoBank Virtual Globe -- ArcGIS Comparison
ArcGIS KML Layer Functionality