The report replaces the target resource. For example, when a final anatomic pathology report replaces a preliminary anatomic pathology report replaces where the subsequent observation of case and report may be on more or different material (specimen). Note that this is not same concept as DiagnosticReport.status = preliminary of final, but industry definition of preliminary and final.
API
Project FHIR API
This is the location where you can find your resource using a FHIR client.
Simplifier FHIR API
The global endpoint is where users can search for all resources in Simplifier. Resources have a globally unique guid Id here.