• Business (conceptual) level: integration with is used to define the business function architecture concepts. These concepts can be implemented by objects at the logical level and be described by data models.
See "HOPEX Information Architecture - Business Layer", page 1.

• Logical level: intended for clients seeking to develop general business-oriented models. Here it consists of modeling data of a domain, application or business process. It represents what we wish to do and where we want to go, irrespective of technical questions related to implementation. Data is represented in a data model or a class diagram.
See: "HOPEX Information Architecture - Logical Layer".

• Physical level: consists of defining models intended to persist in a DBMS. It comprises detailed specifications for production of the physical diagram of the repository. It is represented by the relational diagram.
The physical level also defines the way in which data is stored and how it can be accessed. It enables use of data by DBMSs.
See "HOPEX Information Architecture - Physical Layer".