It is easy to think of metadata as a few information fields that you tack onto an article when you submit it to a CMS. In this vision, metadata is something fairly small, a triviality in comparison to the content itself.
The reality is just the opposite; for any piece of content or data, the metadata is bigger than the data. Metadata is data that explains data. And since data needs to be explained to be useful, metadata also needs metadata to explain it. This means that behind every piece of data there is a metadata cascade that eventually leads back to unstructured stories. Therefore the metadata for any given piece of data or content is all of the data that explains the entirety of that data/content. That’s a lot.