After you create an article, you can get a general idea of how it will look on the web by using the Preview tab. The Preview tab displays all publishable information. This includes attributes, body text, images, hyperlinks, and forms. Because you can customize display options during publication, the preview does not necessarily reflect the published view of the article.
You can get a more accurate preview of your article after it's been added to a content page. See Previewing and Publishing Channels.