All systems that provide BW with data are referred to as source systems. These can be:
You define source systems in the Data Warehousing Workbench in the source system tree. To define a source system, choose Create in the context menu for the folder in the source system type.
DataSources are used to extract and stage data from source systems. The DataSources divide the data provided by a source system into self-contained business areas.
The graphic below provides an overview of the data transfer sources supported by BW and shows the interfaces that you can use: