Hi Jamal,
I want to clearify some things for you by giving an example of an arcgis enviroment.
I want to publish a service which is going to be used by civilians who report unsafe road situations.
I need 4 things: arcgis Desktop
A (geo)database
Arcgis Server
a way to communicate the service with the civilians that means I will need a Portal ( arcgis online or Portal for arcgis)
The arcgis Desktop is going to be used to publish our connection with the (geo)database to our arcgis server.
To manage the database we need at least license level standard. Basic doesn't do the tric.
(Set up an enterprise geodatabase in SQL Server—Help | ArcGIS for Desktop )
You publish your data to your arcgis Server with feature access. With a basic license you only can publish feature services with read-only functionality. With standard and advanced you can publish with read and write functionality.
The difference relevant for our example between Arcgis server license X Workgroup or Enterprise is that workgroup ships with MSQL server express 2012 which is limited up to 10GB. The difference between them is more in terms of capacity and not in terms of functionality like the license level. ( You can check these things in the functionality matrix).
If you plan some purchases or so you should certainly ask your local esri commercial representative.
Lieven