Taxonomy

Quick Definition

A taxonomy is a system for classifying and grouping content in WordPress. The two built-in taxonomies are Categories (hierarchical) and Tags (flat). You can also create custom taxonomies.

WordPress developer documentation for taxonomies

What Is a Taxonomy?

A taxonomy is "a fancy word for the classification/grouping of things." Built-in: Categories (hierarchical) and Tags (flat). Register custom ones with register_taxonomy().

Examples: Genre (books), Color (products), Location (real estate), Cuisine (recipes).

Stored in: wp_terms, wp_term_taxonomy, wp_term_relationships.

Why It Matters

Good taxonomy structure improves navigation and SEO. See our SEO checklist and plugins guide.

Sources: Developer.WordPress.org — Taxonomies, WordPress.org — Taxonomies, Developer.WordPress.org — Categories, Tags & Custom Taxonomies

Related Terms

CategoryA category is a way to group related WordPress posts under a broad topic. Categories are hierarchical — you can create subcategories — and every post must belong to at least one category.Custom Post TypeA Custom Post Type (CPT) lets you create new content types in WordPress beyond the default Posts and Pages — like portfolios, testimonials, events, or products.TagA tag is a keyword you assign to a WordPress post to describe its specific topics. Tags are optional, non-hierarchical, and help readers and search engines understand what your content is about.

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