DLL/EXE acts as a buffer between an FDM application and a target application. DLL/EXE files contain the instructions that enable FDM to communicate with specified target or source applications (connecting to the database, loading data, extracting data, and so on). Each DLL file contains the API calls for a specific target or source application, thus enabling a FDM application to be flexible, to integrate with many target systems, and to not have to maintain numerous application-specific calls within itself.