You may be familiar with sitelinks, the links that show up underneath the first search result and which lead to specific pages deeper within the site. Sitelinks enable users to jump directly to important parts of a site, which is often useful for large, complex websites. Sitelinks have the additional advantage of giving users an overview of a website's content by highlighting some of the popular parts of the site. For webmasters, sitelinks are also beneficial because they help to expose parts of your site that users may not know about. For instance, a search for NASA provides links to a gallery of images, a page about Space Shuttle and ISS missions, and so on:

Until now, sitelinks have only ever appeared on the first search result, and so at most one site could have sitelinks per query. We're now launching an expansion of sitelinks: a single row of links can now appear for results that didn't show sitelinks before, even for results that aren't in the first position. This means multiple results on one query can now have sitelinks. Up to four sitelinks can show up right above the page URL, instead of the usual two columns below the URL of the first result.