Last week, Google introduced the Knowledge Graph, a new search technology designed to help users find new information quickly and easily in the SERPs by providing facts about people, places, and things to search queries right next to their search results. For instance, a query for Marie Curie provides the regular search results on the left and a quick biological sketch on the right along with related searches. This can immediately give users what they want or they can click for more information.
As Google further explains it on the official Google Blog, a search for Taj Mahal could result in many meanings -- the beautiful monument in India, a GRAMMY Award-winning musician, a casino in Atlantic City, or many retail businesses with that name. So which one does a user mean? Now Google offers a technology that understands real-world entities and their relationships, a move away from keyword strings.
For over a decade, Google search has focused heavily on matching keyword strings to queries. Over time, Google has included more and more signals in its search algorithm, changing the weight of different signals. Recently, Google seems to be focusing on semantic web technology with support for rich snippets and schema.org. The Knowledge Graph is an innovation that borrows from the ideas of the semantic web. "Google is moving toward developing a complete semantic search platform and has been since announcing support for schema.org," said semantic web expert Barbara Starr of Ontologica. Eric Miller, who once led the Semantic Web Initiative for the World Wide Web Consortium (W3C) at MIT, has described the semantic web as "a system that takes individual points of data on a network, such as documents or digital media, and allows users to describe the connections between these points in a way that makes the points of data more accessible and useful." These are the ideas that now allow Google to move toward a new way of searching for the concepts that the words describe rather than for pages that match query terms.
As stated in Google's blog, the Knowledge Graph allows users to search for things, people, or places that Google has in its database -- like celebrities, cities, buildings, movies, works of art, etc. -- and immediately get information relevant to their query.
According to Google, its Knowledge Graph includes but is not limited to information from Freebase, Wikipedia, and the CIA World Factbook and currently contains more than 500 million objects, and more than 3.5 billion facts about these different objects and the relationships between them.