The following diagram illustrates two distinct conversations: a conversation on the initiator's/buyer's side and a conversation on the fulfiller's/seller's side. The diagram shows that an initiator and a fulfiller in a conversation both send Chem eStandards payload to each other by sending the document to the pub.estd.chem:receive service. To send an internal business document from a back‐end system to the webMethods Chem eStandards Module, the initiator and the fulfiller use the pub.estd.chem:processDocument service. To send a business document from the webMethods Chem eStandards Module to a back‐end system, the initiator and the fulfiller use a site‐written service. The diagram uses the OrderCreate process as an example. For further explanation, see the sections that follow the diagram: