When you edit a library item, you can update all documents that use that item. If you choose not to update, the documents remain associated with the library item; you can update them later.
You can rename items to break their connection with documents or templates, delete items from the site’s library, and recreate a missing library item.
When you delete a library item, Dreamweaver removes it from the library but doesn’t change the contents of any documents that use the item.