Topic Maps in Crystallize let you define classifications and taxonomies that can be assigned to products, documents, folders, and even media assets. They allow you to create multi-dimensional structures that go beyond a traditional one-dimensional catalogue hierarchy.
Where the catalogue defines where an item lives in your product universe, Topics define what the item is about.

In the screenshot above, a Flavour topic map is shown with hierarchical topics:
This taxonomy could be applied to coffee products, enabling customers to filter by flavour profile in a storefront, or for internal classification in a B2B setting.