Before you set out to create your various stores, your first step is to create the necessary categories that represent the products that you will be selling in your Store level. In Magento 2, the catalog contains all the products you have in your store. Categories are the hierarchal classification of your products and how they will be grouped and represented to your shoppers. Therefore, when we refer to your catalog, we mean the list of products you sell. A product in your catalog can be linked to one or more categories (or none at all).

Each Store entity that you create in Magento 2 must be assigned to one root category. Unlike other categories, the root category is never visible to your customers. It is only the topmost category of a Store level; all other categories are subcategories of the root category.

Let's think of this association in this manner: a Store level is connected to a root category. A root category is the parent of each top-level product category in your...