Category management allows for you to group products into categories for display in your store. B2C and B2B groups can have different categories and thus a different category structure. You may also overwrite B2C categories with the category configuration from B2B.
A product is not displayed on your site until you assign it to a category and make that category visible to the appropriate group (B2B and/or B2C).
By clicking the Tools dropdown, you can access additional options such as importing and exporting product category assignments in bulk.