ADMIN: System → Configuration → XXX Tab
Tags are descriptors that you can assign to any product to help you organize and remember them. They’re essentially keywords or keyword phrases. Any logged in user can add as many tags to a product as he/she wants and rename or delete them later. Tags will be viewable by everyone browsing the product, and will display in a block on the product info page. The admin has to approve a tag the first time it is used, before it appears in the front-end. Once the tag has been approved by the Store Owner it is free for use on other products, and will not have to be approved again.