The Taxonomy module allows you to classify the content of your website. To classify content, you define vocabularies that contain related terms, and then assign the vocabularies to content types. For more information, see the online handbook entry for the Taxonomy module.


Creating vocabularies
Users with sufficient permissions can create vocabularies and terms through the Taxonomy page. The page listing the terms provides a drag-and-drop interface for controlling the order of the terms and sub-terms within a vocabulary, in a hierarchical fashion. A controlled vocabulary classifying music by genre with terms and sub-terms could look as follows:
  • vocabulary: Music
    • term: Jazz
      • sub-term: Swing
      • sub-term: Fusion
    • term: Rock
      • sub-term: Country rock
      • sub-term: Hard rock
You can assign a sub-term to multiple parent terms. For example, fusion can be assigned to both rock and jazz.
Terms in a free-tagging vocabulary can be built gradually as you create or edit content. This is often done used for blogs or photo management applications.
Assigning vocabularies to content types
Before you can use a new vocabulary to classify your content, a new Taxonomy term field must be added to a content type on its manage fields page. When adding a taxonomy field, you choose a widget to use to enter the taxonomy information on the content editing page: a select list, checkboxes, radio buttons, or an auto-complete field (to build a free-tagging vocabulary). After choosing the field type and widget, on the subsequent field settings page you can choose the desired vocabulary, whether one or multiple terms can be chosen from the vocabulary, and other settings. The same vocabulary can be added to multiple content types, by using the "Add existing field" section on the manage fields page.
Classifying content
After the vocabulary is assigned to the content type, you can start classifying content. The field with terms will appear on the content editing screen when you edit or add new content.
Viewing listings and RSS feeds by term
Each taxonomy term automatically provides a page listing content that has its classification, and a corresponding RSS feed. For example, if the taxonomy term country rock has the ID 123 (you can see this by looking at the URL when hovering on the linked term, which you can click to navigate to the listing page), then you will find this list at the path taxonomy/term/123. The RSS feed will use the path taxonomy/term/123/feed (the RSS icon for this term's listing will automatically display in your browser's address bar when viewing the listing page).
Extending Taxonomy module
There are many contributed modules that extend the behavior of the Taxonomy module for both display and organization of terms.