The PDF file is comprised of text and graphics and it may contain entire files inside them as attachments. This makes exchanging sets of documents easier and more reliable. The Attachments pane provides you a central place to view, insert, delete, and export attachments. Also please note that if you move the PDF file to a new location, the attachments inside it also move with it. The attachments may include links to or from the parent document or to other attachments.