Portable Document Format (file format) (PDF) The native file format for Adobe Systems' Acrobat. PDF is the file format for representing documents in a manner that is independent of the original application software, hardware, and operating system used to create those documents. A PDF file can describe documents containing any combination of text, graphics, and images in a device-independent and resolution independent format. These documents can be one page or thousands of pages, very simple or extremely complex with a rich use of fonts, graphics, colour, and images.
http://adobe.com/products/acrobat/adobepdf.html. ["The Portable Document Format Reference Manual", Adobe systems, Inc. Addison-Wesley Publ. Co., ISBN: 0-201-62628-4]. Last updated: 2000-09-08