A business layer is a collection of metadata objects that map to specific data in a database or an OLAP cube. The metadata objects include the following:
Dimensions
Measures
Attributes
Predefined conditions
Navigation paths
When a business layer is complete, it is published to the SAP Business Intelligence Platform as a universe. A universe is a published .unx file that includes all the components of the universe.
The principle role of the business layer is to define and organize the reporting data in a way that is logical to the business users.