Taxonomier

Taxonomier (taxonomies) are structured schemes for classifying objects, concepts, or data into nested groups. They provide a controlled vocabulary that enables consistent labeling, retrieval, and interoperability across systems. The core idea is a hierarchical arrangement in which items are placed within levels of specificity.

In biology, taxonomic systems organize organisms into ranks such as kingdom, phylum, class, order, family, genus, and species, with modern practice often extending or revising these levels to reflect phylogenetic relationships. In information science, libraries, and digital commerce, taxonomies organize content, resources, and products. They support search, browsing, metadata alignment, and navigation, and may be monohierarchical (a single tree) or polyhierarchical (multiple parent categories). Faceted taxonomies allow items to be classified along independent dimensions, improving flexibility.

Taxonomies are created and maintained through governance processes that define scope, preferred labels, and relationships between terms. They typically include synonyms and broader/narrower terms, as well as versioning and mappings to other vocabularies or metadata standards. Effective taxonomies balance domain accuracy with usability, linguistic variation, and scalability as knowledge domains evolve.

Differences from related concepts: a taxonomy focuses on hierarchical classification, whereas ontologies typically include richer relationships, constraints, and semantics beyond tree structures. Folksonomies rely on user-generated tags and may lack a controlled vocabulary, which can hinder consistency and interoperability.

Historically, taxonomy has roots in ancient classification, with contributions from Aristotle and Linnaeus laying the groundwork for biological taxonomy, and later developments shaping information organization, library science, and data management.