# D - Dependency Inversion (DIP) ## About {% hint style="danger" %} The closest to business rules, the higher the level. {% endhint %} High level modules must not depend in low level ones. Both must depend on abstractions and not implementations. * Separated *(independent)* modules, must not have direct dependencies between them. * A class must not know the implementation of other classes methods, but know only the interface of that class.