When taxonomies are arranged hierarchically, it means that successive categories, ranks, grades, or interrelated levels are being used. In a hierarchy, a user would have to select a labeled grouping to find things within it. A hierarchy of movies might look like this:
Hierarchies tend to follow two patterns. First, a broad and shallow hierarchy gives the user more choices up front so they can get to everything in a few steps. As an example, in a grocery store, you choose an aisle, and each aisle has certain arrangement of products, but that's as deep as you can go.