Description logics are a family of logics that are typically (always?) less expressive than full first-order [predicate logic] (FOPL), but have more efficient reasoning procedures available (e.g. the procedures are ''decidable''). Description logics share some characteristics with [frames], [semantic networks], and [object orientation%|%object oriented] knowledge representations. In particular, they usually take an object-centred view (rather than concentrating on relations, as in FOPL), and have some notion of a subsumption relation built-in (similar to [inheritance]). Thus, description logics are often used for describing the objects in some domain as a taxonomy or [ontology], and are popular in the [semantic web]. ---- [NEM]: My knowledge of description logics is fairly basic, so there may be errors in the above. <> Glossary