Open Graph is a special page markup protocol that lets webmasters influence the social snippets of their shared URLs. It is the Open Graph tags' data that determines the title, description and thumbnail image that accompany a URL when someone posts it to social networks. Right now Open Graph markup is supported by all the major social networks, including Facebook, Twitter, Google+, Pinterest, LinkedIn, Instagram and others. The Open Graph tags need to be placed within meta tags in the head of a webpage. And they must be present on every page that may be shared on social networks to make sure it gets the most relevant and compelling snippet.