Product Categories offer you a way to group similar Products together, rather than having all Products in one big list.
Each Product can be allocated to a Category when you Edit a Product or Add new Product. You can create as many Categories as you need.
Each Category has a name and optional sequence number. The sequence number can be used to specify the order in which Categories are listed (lowest sequence number first). Categories with the same sequence number will be listed alphabetically. The default category is always shown last.