Questions regarding the system modeling functionality of the Wolfram Language.
The system modeling functionality of the Wolfram Language that has been integrated into Mathematica as of Version 11.3.0.
While there is some overlap with questions regarding system-modeler, questions with the tag system-modeling should be on the system modeling functionality that has been integrated into the Wolfram Language itself.
Questions regarding the interaction with Wolfram's System Modeler and its specific functionality (e.g. the graphical user interface for building system models) should have the tag system-modeler or in certain, intersecting cases, both tags.