PDF files are especially useful for documents such as magazine articles, product brochures or flyers in which you want to preserve the original graphic appearance online. A PDF file contains one or more page images, each of which you can zoom in on or out from. You also can page forward and backward. PDF files are desirable in many situations, including when graphic design development team members are working at a distance and need to explore design ideas online, when help people need to see the printed book that users are looking at and when a printed document is to be distributed online with its appearance preserved. Acrobat's PDF files are more than images of documents.
Files can embed type fonts so that they're available at any viewing location.
They can also include interactive elements such as buttons for forms entry and for triggering sound and Quicktime or AVI movies. PDF files are optimized for the web by rendering text before graphic images and hypertext links. Ping is a basic network program that lets you verify that a particular network address exists and can accept requests. The verb ping means the act of using the ping utility or command. Ping is used diagnostically to ensure that a host computer you are trying to reach is actually operating.