All users make use of WordPress taxonomy, even if they don’t understand the concept or are unfamiliar with the term. In biology, animals and plants are divided into categories in the Linnaean taxonomy. WordPress taxonomy is derived from this. It’s used to group your posts and your types of posts into different categories. In most cases, users use two different taxonomies to categorize their posts: tags and categories.
In addition to these two common taxonomies, you can also create custom taxonomies that allow you to better group your posts. If you use your WordPress blog to write movie reviews, for example, your first instinct may be to use categories for different genres. However, custom taxonomies provide options that categories don’t. Instead, you might create a custom taxonomy for Genre and then add different topic terms to it for each. You would have romance, science fiction, mystery, etc.
By doing so, your users can sort the different movie reviews by topic. This can make it much easier to find what they’re looking for. You can also create hierarchies within taxonomies. That means the main topics can have subtopics. Under science fiction, you could have subtopics for space adventure, time travel, comedy, etc. to further organize your reviews.