When we work with WordPress, we deal with data that we commonly know as posts, pages, media, comments, options etc. However, the REST API has required us to rethink what some of these data structures are and how they should work, particularly in regards to metadata and options, which have historically been an undefined dump of arbitrary data. This session provides an abstract overview of how data in WordPress is structured and gives insight on questions like: How are post types and taxonomies related? What makes metadata different from options? Where does my own data fit in? If you are developing for WordPress, it is crucial to know some of these concepts. In recent years, WordPress has started to make some structure out of its previous data mess, but is still only touching the surface. And we can all contribute to figuring it out together.