IDoc
IDoc, short for Intermediate Document, is an SAP document format for business transaction data transfers.
Non SAP-systems can use IDocs as the standard interface (computing) for data transfer.
IDoc is similar to XML in purpose, but differs in syntax. Both serve the purpose of data exchange and automation in computer systems, but the IDoc-Technology takes a different approach.
While XML allows having some metadata about the document itself, an IDoc is obligated to have information at its header like its creator, creation time etc. While XML has a tag-like tree structure containing data and meta-data, IDocs use a table with the data and meta-data. IDocs also have a session that explains all the processes which the document passed or will pass, allowing one to debug and trace the status of the document.
Different IDoc types are available to handle different types of messages. For example, the IDoc format ORDERS01 may be used for both purchase orders and order confirmations.
IDoc technology offers many tools for automation, monitoring and error handling. For example, if the IDocs are customised that way on a particular server, then a user of SAP R/3 system creates a purchase order; this is automatically sent via an IDoc and a sales order is immediately created on the vendor's system.