Ontology languages and description logics

Abstract

Ontology-driven software technology is expected to improve MDSD with better facilities for modelling, better understanding of relationships between artefacts and better handling of complexity, via ontology-based knowledge representation (KR) techniques and reasoning techniques. The term ontology originates from philosophy, where it refers to a unique description of the universe or ’things that are’. In modern information technology, especially in the Semantic Web, an ontology is a model of (some aspects of) the world, which introduces key vocabulary (such as concepts and relations) of a target domain and their meanings. This chapter introduces the standard ontology language family web ontology language (OWL) and its underpinnings—description logics. In this chapter, we first introduce description logics (DL) [11] and some simple DL languages in Sect. 3.1. Then in Sect. 3.2 we present the web ontology language (OWL) family, which is endorsed by the world wide web consortium (W3C). We pay special attention to OWL 2 profiles, which are tractable sub-languages in the OWL family. They play an important role in scalable reasoning services (cf. Chap. 5). Section 3.3 concludes this chapter.