A taxonomy is a system for grouping and organizing content in WordPress. Categories and tags are the two built-in taxonomies, but WordPress can support custom ones too, depending on what a site needs.
Think of a taxonomy as the overall organizing concept, while individual categories or tags are the specific terms within it. “Category” is a taxonomy; “Desserts” is a term inside that taxonomy.
Custom Taxonomies
Beyond categories and tags, developers can create entirely custom taxonomies suited to a specific site. A movie review site, for example, might add a “Genre” taxonomy, or a real estate site might use “Property Type.”
Why This Matters
A well-planned taxonomy structure makes a site easier to browse and helps search engines understand how your content relates together. It’s worth thinking through your taxonomy structure early, since reorganizing hundreds of posts later can be a tedious task.