This introduction presents the main motivations for the development of Description Logics (DLs) as a formalism for representing knowledge, as well as some important basic notions underlying all systems that have been created in the DL tradition. In addition, we provide the reader with an overview of
the entire book and some guidelines for reading it.
We first address the relationship between Description Logics and earlier
semantic network and frame systems, which represent the original heritage
of the field. We delve into some of the key problems encountered with the
older efforts. Subsequently, we introduce the basic features of DL languages
and related reasoning techniques.
DL languages are then viewed as the core of knowledge representation
systems, considering both the structure of a DL knowledge base and its associated reasoning services. The development of some implemented knowledge representation systems based on Description Logics and the first applications built with such systems are then reviewed.