Description Logics (DLs) are a family of knowledge representation formalisms designed for the representation of and reasoning about the terminological knowledge of an application domain. They are descendants of semantic networks, frame-based systems, and KL-ONE, and come with well-defined semantics and (provably) correct inference algorithms. As in other areas, the more (expressive power) you want for your application, the more (time and space for solving inference problems) you must pay. Since the beginning of DLs, this trade-off was subject to numerous investigations. Interestingly, over the last decade, our intuition of ``tractable'' inference problems has tremendously changed.

In this introductory talk, Sattler will give a flavour of what DLs are about, and how they can be used. After a brief introduction to Description Logics, she will present two applications of DLs: how a DL-based system can be used for building/maintaining ontologies, and how such a system can be used to support conceptual modeling.