For brevity, this list does not include third-party vocabularies. To view an exhaustive list of all vocabularies in use on ONS Geography Linked Data including ones provided by third parties - see the results of this query.
A concept scheme is a collection of concepts about a topic. A concept scheme often acts as a list of possible values for a certain property of a resource (i.e. possible objects for RDF triples).
An ontology is a set of classes and properties about a certain topic area. These can be used for resources' types and properties (predicates) respectively.