The taxonomy component is one of the most popular features because users often want to create categories to organize content by type. A simple example would be organizing a list of music reviews by musical genre.

Taxonomy is the study of classification. The taxonomy module allows you to define vocabularies (sets of categories) which are used to classify content. The module supports hierarchical classification and association between terms, allowing for truly flexible information retrieval and classification. The taxonomy module allows multiple lists of categories for classification (controlled vocabularies) and offers the possibility of creating thesauri (controlled vocabularies that indicate the relationship of terms) and taxonomies (controlled vocabularies where relationships are indicated hierarchically). To view and manage the terms of each vocabulary, click on the associated list terms link. To delete a vocabulary and all its terms, choose edit vocabulary.

A controlled vocabulary is a set of terms to use for describing content (known as descriptors in indexing lingo). The system allows you to describe each piece of content (blog, story, etc.) using one or many of these terms. For simple implementations, you might create a set of categories without subcategories, similar to Slashdot's sections. For more complex implementations, you might create a hierarchical list of categories.