The universe structure
A universe is a semantic layer that maps a specific data area or several areas in the data warehouse or in any database such as SQL Server, DB2, Oracle, and many others. The universe uses a connection in order to connect to the database, and once it's set, users can navigate to the universe, build queries, and connect through the universe connection to the database, retrieving the most updated data according to the data update date in the database.
The universe represents the data in a lucid manner, so business users don't require database programming knowledge or an understanding of how the database is structured.
What the user does need to know is how the universe is structured: its main business purposes, what kind of queries can be built using it, and what kind of objects can be used to build his reports and where can he find them in the universe.
Traditionally, a universe maps a specific data subject such as Sales, Marketing, Human Resources, Logistics...