also see Linking Your Thinking
part of Wiki Theory and Culture
The core essence of Wikis: the ability to Link As You Think by simply typing the page name. What makes this feature beautiful is that you can link to a page that does not already exist.
To link to a page on a Wiki, you refer to the page's name. This is different from the default behavior of the web, which usually requires that you track down a URL (usually designed for machines, not people) to create a link.
The ability to point to a page that does not currently exist is a powerful capability. Ward Cunningham, who invented the WikiWikiWeb, originally observed this behavior when he was doing software design with index cards. He noticed that engineers would place a card on the table without writing anything on it and talk about it as if it was a real entity, even though it had not yet been named or described.