The document discusses Google's +1 button and how it works. The +1 button allows users to publicly recommend web pages to their Google contacts, indicating they think the page is useful. When a user clicks the +1 button on a page, it tells Google they recommend it and can provide a boost to the page's search ranking. Only logged-in Google users can see each other's +1 recommendations. The more +1s a page gets, the higher it may rank in Google search results. The document encourages adding the +1 button to websites to try and improve search engine optimization and visibility.