One of Drupal’s best features is taxonomy. This tutorial gives an introduction on how to use Drupal’s taxonomy system.
New users to Drupal sometimes find taxonomy difficult to understand at first. I recommend reading all the way through this tutorial once. If the first part doesn’t make sense, I hope that it will by the end.
Taxonomy can be thought of as categories or tags. Drupal taxonomy is made up of vocabularies and terms. A vocabulary is a set of terms and terms are just another word for categories.