i am confused that so many site are using Open Graph protocol in website. please suggest and describe that What is the The Open Graph protocol and what is use of it in website?
http://en.wikipedia.org/wiki/Facebook_Platform#Open_Graph_protocol is pretty self explanatory - The Open Graph protocol enables developers to integrate their pages into the social graph and Social Graph is nothing but a distribution of how you are connected to your network. Sites are using open graph to embed facebook elements