" The database, the query language, and even the schema are technical details that have nothing to do with the business rules or the UI. They will change at rates, and for reasons, that are independent of other aspects of the system. Consequently, the architecture should separate them from the rest of the system so that they can be independently changed. Thus we find the system divided into decoupled horizontal layers—the UI, application-specific business rules, application-independent business rules, and the database, just to mention a few. "

― Robert C. Martin , Clean Architecture