SAP uses IDocs to integrate with Electronic Data Interchange (EDI) systems. You can import IDoc definitions as SAP ECC source definitions. An IDoc is a generated text file that contains a hierarchical structure consisting of segments. Each segment is an SAP structure defined in the SAP system.
An IDoc has the following components:
Header.
The header contains control information, such as creation date and status. The control information is in an SAP structure called EDIDC.
Data records.
The data records are in an SAP structure called EDIDD.
Import IDoc definitions when you want to extract data from the EDIDC and EDIDD structures.
If you want to use IDocs to receive data from mySAP applications and send data to mySAP applications using ALE, do not import IDoc definitions. To use ALE to send and receive IDocs, use SAP/ALE IDoc Interpreter and SAP/ALE IDoc Prepare transformations in a mapping.