I read documentation from Do you use Collector for ArcGIS | Questions & Answers . I am not clear about named users ArcGIS Online hosted feature service AND ArcGIS Server from SDE geodatabase. I am planning to create tree inventory with possibly attachments for inspectors. Do you recommend ArcGIS Online or ArcGIS Server? If using ArcGIS Server, how do I connect insecptors for track editors since they are non- GIS users? If using ArcGIS Online hosted feature services, can it connect to SDE geodatabase directly? Please advise. Thank you.