The document discusses EDI architecture, ALE, and IDOCs. EDI architecture consists of EDI-enabled applications, the IDoc interface, and an EDI subsystem. ALE supports distribution of business functions across loosely coupled SAP R/3 systems and connections to non-SAP systems. The key difference between ALE and EDI is that ALE is used for integrated processes across SAP systems while EDI is for exchange of business documents between partner systems. Both ALE and EDI use IDOCs for data exchange. IDOCs are data containers with a specified format that are exchanged between systems to transfer data.