SAP Integration Basics

There are two ways of integrating external systems with SAP R/3.

1. ALE
2. BAPI
   

ALE - Application Link Enabling, part of SAP's integration layer enables integration between SAP R/3 systems and other external systems. It is best suitable for use with batch objects and asynchronous integration.

BAPI - Business APIs are SAP's APIs to interact with SAP R/3. They are implemented as RFC functions for an SAP business object's (e.g. Customer, Vendor etc) methods. BAPI is best suitable for real time synchronous integration where the BAPI method is invoked as a request and the resultant data is returned as a reply (request-reply paradigm).