Remote Function Call is a proprietary SAP interface. Remote Function Call (RFC) is the standard SAP interface for communication between SAP systems. The RFC calls a function to be executed in a remote system. Remote function calls may be associated with SAP software and ABAP programming and provide a way for an external program (written in languages such as PHP, ASP, Java, C, or C++) to use data returned from the server. Data transactions can get data from the server, and can insert data into server records as well. SAP can act as the Client or Server in an RFC call.