Catalog → Products → Edit Product
Categories: Category or categories where the product will be displayed on the storefront.
Product Categorization in AbanteCart:
Category Assignment: You can assign a product to one or more categories. This determines where the product will be visible on your storefront's category pages.
Multiple Categories: A product can belong to multiple categories. This is useful for products that fit into more than one category (e.g., a "red dress" might belong to both "Dresses" and "Red Clothing").
Subcategory Inheritance: This is a very important point. If you assign a product to a subcategory, it will automatically also be visible in the parent category (and any higher-level ancestor categories). This is called category inheritance
Related Products: offering to customers the products related to the current product when customers are viewing this product.
Set Related in the Grid
Related products can be assigned to any products in Admin → Catalog → Products grid. On this page select products in the list and choose set related in the right bottom of the grid.
Stores: select store where product will be displayed. If you're managing multiple Stores, you can select the stores to which this product is associated by checking the checkbox next to the Stores from which you want the product to be available.
read more about multi-store set up in this article
Even if your product is not assigned to any category or assigned to the category it is still available in search, as a related product, in data listing blocks (specials, bestsellers) and with direct product link.