In shortAn IDoc (Intermediate Document) is the standard segment-based document format SAP uses for asynchronous data exchange between systems.
An IDoc is a data container that carries a business event (for example a material document or a production confirmation) in defined segments. Inbound and outbound IDocs are processed in SAP and each carries a status history, so you can see which document was processed, failed or is waiting.
IDocs are asynchronous: the sender continues without waiting for the outcome. This means preventing duplicate sending and designing how a failed document is reprocessed must be done up front.
In OPC Router projects
The OPC Router SAP plug-in connects through RFC, BAPI and IDoc. Which interface to use is chosen in the project according to the SAP version and business process.