Universes allow end-users the ability to pull data without knowing the structure of the underlying data. The interface is drag and drop style so no technical knowledge of SQL is required and reporting is made easier. Each universe represents a set of data available for reporting.
Educational Data Warehouse Universes are created to work together easily, with similarly named and organized objects. The data you can pull within a universe can come from multiple sources, but you have access in one place. For instance, the Course Exams universe pulls test scores for students from Examsoft and NBME.