Categories (also called hierarchies or nodes) are hierarchical structures to organize items and services into intuitive groups. Organizing items in this way simplifies item discovery and lifecycle management. There are two types of categories - Primary and Alternate. They enable you to create, organize, and distribute item data.

- Primary category is the original catalog tree with nested levels of categories that place each item where it belongs, within a category. For example, Computers is a parent category with Laptops and Desktops as children categories, and MacBbook Pro is an item within Laptops. This organization can be represented as Computers > Laptops > MacBook Pro.

- Alternate categories serve as alternate organizations of the Primary category. Their main purpose is distribution management by displaying items on your website based on separate browsing structure configurations you set to help you achieve various merchandizing objectives, such as organizational requirements, multi-regional assortments, multi-channel assortments, and collections. For example, a company that sells, repairs, and supports computers and related items and services will have a Primary category containing a full list of their SKUs. However, this Primary category is not granular enough to use on their storefront. Hence, multiple Alternate hierarchies are created to target specific shopper segment experiences. For laptop consumers they'll have one Alternate category, which lists all the laptops and PCs. For large businesses they'll have another Alternate category, which lists all commercial laptops, PCs, printers, and servers. Both of the Alternate categories act as filters of the Primary category, tailored to the purpose of that merchandising strategy.

Category, a subset of PIM endpoints, aims to simplify catalog management by letting you create, update, and get one or more categories, category attributes, and item attributes. In addition, you can add and update category sources, source exclusions, and item attribute conditions.