Google has introduced an expansion of sitelinks, which brings the possibility of a more limited version of sitelinks being displayed for multiple results on a search results page. Sitelinks are links to additional pages on a website that are shown underneath a result from that website. The decision whether to show sitelinks for a given query and what links to show is determined algorithmically. In a post on the Google Webmaster Central Blog announcing the expansion, Google explains that the purpose of sitelinks is to “enable users to jump directly to important parts of a site, which is often useful for large, complex websites” and to give “users an overview of a website’s content by highlighting some of the popular parts of the site.”
Originally, sitelinks were only shown for the first result of a search with three to eight links shown in two columns. If your search for Microsoft you can see example of this along with a search box, for searching within the given website, that is sometimes shown under the sitelinks. The expansion introduces one-line sitelinks, which show up to four links to other pages on the website. The one-line sitelinks can show up for multiple results, including the first result.
In the post Google also announced changes in the ability for websites to block pages from their websites, through Google’s Webmasters Tools, from being shown as sitelinks. Google will be “speeding up our response time” in blocking pages and expanding the blocking, which is currently limited to blocking pages shown as sitelinks for a website’s homepage, to any page on a website that displays sitelinks.