Protected boards live at the very bottom of your profile in a section only visible to you. Pins on a protected board may surface in search results and others' home feeds, but others can only access the protected board if they have a direct link.
Pins created using the bulk editor are automatically added to a new protected board every time the bulk editor is used. Protected boards are named by default and will appear as: Created by Ads Bulk Editor date/time. You can rename the protected boards, edit the board descriptions and change the board category to reflect the content of your Pins by editing the board settings.
Shopping product Pins are also added to protected boards. When you add Shop the Look products through the "Add a Pin" flow, you create a Product Pin that lives on a protected board. You can view your Shop the Look Product Pins, at pinterest.com/[your_pinterest_username]/products-you-tagged/