Trees vs facets vs tags
... any CMS managing any sizeable amount of data needs to support trees. Anything else will lead to an unmanageable mess. However, systems with smaller sets of content, especially with a smaller group of authors, can get away with tagging as well. Facetting only really works well with a system that stores content that is highly structured at least on a per node type basis.http://www.sitepoint.com/cms-content-organization-structures-trees-vs-facets-vs-tags/