Bongo4U has a basic built-in catalog for the display of products or other items.

Products can be organized into categories.

Each product's category is listed on its product record.

If you wish to rename an existing category name, then edit each of the products in the old category name, changing the category name on each product record to be the new category name.

Once no products use a given old category name, then that old category name disappears from your category and product listings.