(one of the terms used on this wiki)
Dokuwiki in general allows people to arrange their pages in namespaces, which are equivalent to folders or directories. See the page about namespaces in Dokuwiki namespaces, which explains this feature.
The purpose of namespaces is not to be confused with terms. A term (or tag or theme or topic) brings together pages thematically; while a namespace is a logical division that allows different access rights, which will allow parts of the wiki to be opened (or not) to collaboration.