taxonomy

Taxonomies is an important part of Drupal, of course depending on your needs, but I haven't built a website on Drupal without using taxonomies for tags or categories in some way.

From the website of Kodamera: "There are many ways of exporting and importing taxonomies and terms in Drupal, but one of the more simpler ways is to use the Taxonomy CSV import/export module. It lets you choose one of many taxonomies, like the tag taxonomy for example, export it to a comma-separated list which you then can import in a similar way."