Content servers are used to save large quantities of documents, either within CRM on the SAP database, or in an external system via an SAP-certified interface. The Document Modeling Workbench in CRM is structured so that one document class (for example, a physical storage place) is available for each business object. A content server therefore contains one storage space for every business object. In CRM systems, documents are stored in the CRM database or on an external content server.