A Product Category is a node in a category tree - the merchandising structure used to organize products for navigation, filtering, and reporting. Other systems call it a Category, Collection, Department, Product Group, or Taxonomy Node.

Categories are reference data: they exist independently of any product, and products are linked to them through separate assignment records. Categories nest under one another to form a tree, and a single category can belong to more than one Category Set - so the website navigation and the POS department structure can reuse the same category or keep separate ones. Integrations typically sync the tree once (and on change), then manage product-to-category assignments as products flow.