In the latest post to the SitePoint PHP blog Lukas Smith takes a look at content management systems comparing trees versus facets versus tags in content organization.

For several years I have been interested in content repositories as a key aspect of modern CMS. With “modern”, I mean CMS that are not just “page management systems” but CMS that actually manage content, thereby enabling authors to reuse their content on different devices and even different applications. But when evaluating [prismic.io and contentful.com], I noticed a surprising trend: they do not leverage trees, neither as a native storage concept nor as a visualization concept. Instead, they for the most part rely on flat structures with tagging. My gut feeling was telling me that this was a mistake, especially when managing larger content repositories. At the same time I wondered: “Am I just a dinosaur that is missing the ark?”.

He starts with an introduction to the concepts of trees, facets and tags and starts in on the advantages and disadvantages of each. For each topic he shares a brief summary of what they are and a screenshot showing how they could be visualized. He finishes the post with a "tl;dr;" summarizing the points made for those wanting the basics.