Reading a book from cover to cover, for example, is linear learning. You start at one point, and finish at the end of the book. With Web pages, you can start reading, find a link in the text that covers additional material, and go to that link. That link may lead you to another link.

By not completely reading the original Web page and following links, you are accessing information in a nonlinear fashion. This is a powerful and interesting method to learn and perform research.