I've been reading the codex for WordPress closely and am confused about the vague definitions between what a Taxonomy is and what a Category is. For that matter, term is also a word that is used in the description of Taxonomies, but seems used in a manner that hints that it isn't solely limited to a Taxonomy.

Both are described as a way to classify and group together posts. I do understand that Taxonomies are a more general form of categories, but how exactly do they relate to each other?

Is there a subtle difference I'm just not picking up on?

  • I think you should create custom taxonomies for custom post types rather than use the native categories so its less confusing. Commented Jul 31, 2015 at 9:02

3 Answers 3


Taxonomies, as previously described are a collective noun for the following

  • category

  • post_tag

  • post_format

  • link_category

  • custom taxonomy

The first four are built-in taxonomies, while custom taxonomies are taxonomies that are manually created by the user with register_taxonomy. Custom Taxonomies can be hierarchical (like the build-in taxonomy category) or not (like post tags)

The categories and tags that you create in the back end under the 'Posts' screen are in actual fact terms of the taxonomies category and post_tag

You cannot create extra terms in post_format. post_format has built-in terms like post_format_video, post_format_gallery etc. See the codex for all post formats included

enter image description here


I have updated the Taxonomies page in the codex to include my diagram and the missing post_format taxonomy

  • 5
    +1. Just a bit of pedantry: even built-in taxonomies are created via register_taxonomy. 2 times. :)
    – gmazzap
    Commented Aug 18, 2014 at 7:08
  • 1
    Jip, but they aren't manually created by the user. See your point though, I actually should have added that specific detail in my answer. :-) Many thanks Commented Aug 18, 2014 at 7:12
  • To be honest I added the comments to not miss the opportunity to tease WordPress about that stupid double registration of post types and taxonomies :D
    – gmazzap
    Commented Aug 18, 2014 at 7:32
  • 1
    Would be better if when you click the image @goose, it increases in size. Commented Aug 18, 2014 at 7:35
  • 1
    @G.M. hahaha, see the joke in all of this. It's like eating the same piece of meat twice Commented Aug 18, 2014 at 7:45

Category, Tag, Link Category and Post Formats are built in taxonomies.

From Codex

Basically, a taxonomy is a way to group things together.

The names for the different groupings in a taxonomy are called terms. Using groupings of animals as an example, we might call one group "birds", and another group "fish". "Fish" and "birds" are terms in our taxonomy. As an example from WordPress, a category or tag (see next section) is a term.


Category is one of the built-in taxonomy in WordPress.

So to clear things: taxonomy is a way to group things together.

we can create custom taxonomies in WordPress just like built-in ones. For example Carscould be a taxonomy with terms like


there are mainly two types of taxonomies available which are hierarchical and non hierarchical

Category is best example of hierarchical taxonomy and Tag is an example of non hierarchical taxonomy

Not the answer you're looking for? Browse other questions tagged or ask your own question.