This summary is excerpted from an article by John Deubert, author of the Adobe Acrobat X for Windows and Macintosh: Visual QuickStart Guide, published by Peachpit Press.
Deubert says "the most significant addition to how we read text in the modern era is the hyperlink, an active area on the page that, when clicked with a mouse or touched with a finger, causes something to happen. Most links send you to somewhere: Another page of the document, another website, but the possible actions a link can invoke are myriad and various."
The tutorial includes a sample PDF document [PDF: 2.2MB] that can be used to follow along and explore applications of the Link tool, found in the Content panel in the Acrobat X Tools pane.
"It's easy to add links to your own PDF document pages," Deubert says. "Your PDF links can send the users to other pages in the document, view a web page, play a movie, and do any of a wide range of other activities. All you need is Acrobat X and--well, that's all you need, really. And a little practice."
Read his complete six-part article, courtesy of Peachpit, to "learn the process by which links are born in Acrobat X" -- including email links and automatic weblinks created from all URLs within a PDF file. The latter can be a real time-saver over manual link creation in a lengthy document!