What Type of Provider is SDS in ArcGIS Enterprise

[BHK]

Can Someone please let me know what is the SDS provider in ArcGIS Enterprise and when this type of service is created? 

[JoshuaBixby]

I addressed this in a comment to your question on GIS SE, but will post it here as well:

ArcGIS Spatial Data Server (SDS) was a single-release product at 10.1, Esri deprecated it by ArcGIS 10.2 when ArcGIS Server's feature access capability was expanded to support non-geodatabase databases. I can't imagine you are seeing that in the wild these days.

[BHK]

Thanks Joshua, this is weird because we Started ArcGIS Enterprise from 10.6! and I am seeing more than 100 services in SDS provider format!

[JoshuaBixby]

Accoring to Lerman, it appears Esri may have repurposed that provider for Hosted FeatureServer.

[Lerman · Accepted solution]

The provider of Hosted FeatureServer is SDS.