What is a Taxonomy?
A taxonomy is just a way to group things. Whether you realize it or not, you’ve already been using taxonomies. Categories and tags on blog posts are taxonomies. When you use them, you’re telling Wordpress how to group similar blog posts together.
In the case of Mooberry Book Manager, we’re grouping books. MBM Comes with 6 taxonomies out of the box: Genre, Tag, Series, Cover Artist, Editor, and Illustrator.
The Custom fields extension allows you to create your own taxonomies for organizing your books.