There are 3 main layers in ABAP RAP Model–
- Data Modeling & Behavior Layer
- Business Service Provisioning Layer
- Service Consumption Layer
Data Modeling and Behavior Layer contains business objects which are defined by the CDS(Core Data Services) and transactional behavior.
Business Service Provisioning Layer defines the projection views of the behavior to focus on specific aspect of the data model which is exposed as business services through OData protocol.
Service Consumption Layer allows to consume the OData Services and OData web APIs.