Sections of a document are typically part of a document. But the size of sections may vary. To support a team to write collaboratively on the documentation, a larger document may be subdivided into external section documents.

In contrast to modules, sections are not intended to be used by other documents (but they may be used by reference or transclusion). The lifetime of a section is, contrary to modules, bound to the lifetime of its parent document. That is, if the parent document, this section is part of, is deleted, so is the section. Modules on the other side are not bound to the lifetime of documents that reference or transclude them.

If you do not want subdocuments to be bound to the lifetime of the parent document, use another doctype, usually Topics.