Overview of the Data Model 
On the initial screen of the Data Modeler you can call the SAP Architecture model, the SAP Application model or other data models.
SAP Architecture model
The SAP Architecture model is the overall model of the SAP system. It contains all information objects and their relationships with each other.
SAP Application data model
The SAP Application data models are views of the Architecture model. They contain only information objects and relationships that are significant for the respective applications.
Other models
Other models include both SAP models that are used for courses or documentation, and the customer-specific models.