DataView as a development tools is an application itself and is consequently created in the entity relationship model. Just as your application, the system data model consists of entities, relations, and links. The system objects are mapped in the database in the form of system tables and contain the meta data of your application. For creating and managing these meta data there are system forms and lists pointing to these system tables.
Note! You should know the system data model and the system objects of DataView very well if you port complete applications or parts of it using the table loader ( -> Porting Complete Applications). When you do that it is almost always necessary to export or import system tables. Knowing the data model simplifies the selection of these tables during export.
Each system entity models a class of objects which you will create in your application. These are for instance entities, menus, masks, or fields. One data base table exists for each system entity.
The system entities are connected with each other via the following system relations. One data base table exists for each system relation. System relations are used to create and manage relations between application objects, such as relations between entities, mask-field relations or menu-item relations.
System links connect application objects in the system tables without requiring system relation tables. This allows you for instance to link a mask with several context menus. the list of system links is omitted here, because they are only internally relevant.