Overlays and Sling Resource Merger

[AEM_Forum]

Hi,

I understand that from implementation perspective, the main difference between Overlays and Sling Resource Merger is that in case of Overlays, we copy the whole folder structure, which in case of Sling Resource Merger we copy only the to be changed elements and make changes.

How does AEM know whether it is Overlays or Sling Resource Merger that we are doing?

Thanks,

Rama.