|PDF, Portable Document Format|
PDF represents formatted documents. These documents may be structured or simple. They may contain text, images, graphics, and other multimedia content, such as video and audio. There is support for annotations, metadata, hypertext links, and bookmarks.
PDF supports encryption and digital signatures in the document. The encryption capability is also combined with access control information in a way that is intended to manage the uses that a recipient can make of a document.
PDF relies on the same imaging model as the PostScript page description language to render complex text, images, and graphics in a device and resolution-independent manner, bringing this feature to the screen as well as the printer. To improve performance for interactive viewing, PDF defines a more structured format than that used by most PostScript language programs. PDF also includes objects, such as hypertext links and annotations, that are not part of the page itself, but are useful for building collections of related documents and for reviewing and commenting on documents.
[RFC 3778] The application/pdf Media Type.