Service Class Provider
SCP is an acronym for "Service Class Provider" which is the weird DICOM term for a server application. All DICOM network communications occur between an SCP and a Service_Class_User-_SCU
In the vast majority of cases, the Association is initiated by the SCU with the SCP responding, but DICOM does allow Reverse_Role_Negotiation whereby the initiator can request to be regarded as the SCP. In practice, this is only used as part of the Storage_Commitment service.