0
BDC is the good old method of moving legacy data to SAP. BAPI is the new enhanced Application Interface through which data can be uploaded into SAP System. BDC is transaction oriented. ... Whereas BAPI is an interfacing method, through which SAP data can be processed from within SAP or from other non-SAP applications.
1
"BAPIs are remote enabled function modules that provide external access (from standalone JAVA or VB) to an SAP Business Application like ""Create Sales Order"" wrapped in Business Objects. BAPI cannot contain Exceptions.
RFC is a protocol for communication between different systems within SAP environment similar to HTTP. It can contain Exceptions."