A Universe is a business-oriented mapping of the data 
structure found in databases: tables, columns, joins, etc.
  A Universe is a semantic layer between Database and end 
users.
   A Universe can represent any specific application, 
system, or group of users. For example, a universe can 
relate to a department in a company such as marketing or 
accounting.
   A Universe can also pertain to a section within a 
department or just about any set of organized procedures 
such as a payroll or inventory system. 
A Universe consists of a set of objects, grouped by classes