In Databases there are simple ways to model the world and represent Concepts and make Conceptualizations in a less formal way than Description Logics, like UML the Universal Modeling Language or the Entity-Relationship Model.
With this one can also make or describe Ontologies. However, these Ontologies are not really formally defined because with definitions in Entity Relationship models it will be difficult to induce new Knowledge and difficult to make calculations that one can easily do with Logics. This is the reason why one has to use Logics. The reason for the use of Description Logics is that First Order Logic is a little bit too complicated, especially if it comes to Complexity and Decidability. So it is Undecidable for certain reasons and Propositional Logic is much too simple. Therefore one needs something in between, i.e. Description Logics. Description Logics are trying to preserve the expressivity from First Order Logic, while on the other hand maintain decidability and maintain if possible low complexity.
Seminar - Title: String - Semester: String - Begin: Date - End: Date
Person - GivenName: String - FamilyName: String - ...
Person -n-participatesAt-n-> Seminar Person -1-givesLecture-n-> Seminar