Facebook announcement today is about the Graph Search. Facebook Graph Search is a new way to navigate connections between users and make them more useful. Facebook Graph Search starts today with a limited preview, or beta.
When Facebook first launched, the main way most people used the site was to browse around, learn about people and make new connections. Graph Search takes Facebook back to its roots and allows people to use the graph to make new connections.
Facebook Graph Search will appear as a bigger search bar at the top of each page. When you search for something, that search not only determines the set of results you get, but also serves as a title for the page. You can edit the title – and in doing so create your own custom view of the content you and your friends have shared on Facebook.
Graph Search and web search are very different. Web search is designed to take a set of keywords (for example: “hip hop”) and provide the best possible results that match those keywords. With Graph Search you combine phrases (for example: "my friends in New York who like Jay-Z") to get that set of people, places, photos or other content that's been shared on Facebook. Via Facebook.