Controlled vocabulary is an organised and standardised arrangement of
predefined terms (words and phrases) that are used to index content in
an information system with the aim of facilitating information
retrieval. Controlled vocabularies provide a consistent way to describe data. They
are standardized and organized arrangements of words and phrases
presented as alphabetical lists of terms or as thesauri,
ontologies, and taxonomies
with a hierarchical structure of broader and narrower terms. Controlled vocabularies also connect variant terms and synonyms
for concepts, link concepts in a logical order and organise them into
categories. They can
be general and discipline-specific. Using a controlled vocabulary will aid in
searching and finding your data and will make your data more shareable
with researchers in the same discipline.
Ontologies are not controlled vocabularies, but they use controlled
vocabularies to establish a formal specification of a conceptual model
in which concepts and categories of concepts, properties, relationships
among concepts and categories, functions, constraints, and axioms are
defined.