The Taxonomy module is used to create vocabularies. Each vocabulary contains a set of terms. These terms can be used to categorize and group site content in a surprising variety of ways. For example, when visitors view a post on your site for which a term has been assigned, many themes will automatically display the term as well. The term appears as a link. Selecting this link displays a view showing all other content on the site that has been assigned the same term.

The following principles apply to defining a vocabulary with the Taxonomy module:

  • Each vocabulary is made up of a set of terms.
  • A site can have an one or more vocabularies each containing multiple terms.
  • Terms can be ordered into hierarchies.
  • Vocabularies can set for free tagging, which allows editors to define new term whenever they add content rather than having to choose from a predefined list.
  • Terms can be related to each other. This is similar to "see also" in a dictionary.