The Knowledge Graph is a knowledge base used by Google to enhance its search engine's search results with semantic-search information gathered from a wide variety of sources. Knowledge Graph display was added to Google's search engine in 2012, starting in the United States, having been announced on May 16, 2012. It provides structured and detailed information about the topic in addition to a list of links to other sites. The goal is that users would be able to use this information to resolve their query without having to navigate to other sites and assemble the information themselves.
According to Google, the information in the Knowledge Graph is derived from many sources, including the CIA World Factbook, Freebase, and Wikipedia. The feature is similar in intent to answer engines such as Ask Jeeves and Wolfram Alpha.
As of 2012[update], its semantic network contained over 570 million objects and more than 18 billion facts about and relationships between different objects that are used to understand the meaning of the keywords entered for the search.
Conversational search 
During the Google I/O conference in May 2013, Google's Amit Singhal presented on the future of search, explaining that a search engine's three primary functions will need to evolve and that search will need to: 1. Answer, 2. Converse, and 3. Anticipate. As part of his keynote talk, Singhal stated, "A computer you can talk to? And it will answer everything you ask it? Little did I know, I would grow up to become the person responsible for building my dream for the entire world." Conversational search technology was then featured and Singhal introduced the term "hot-wording" to describe search without the need for an interface, whereby the user simply prompts the Google search engine by stating, "OK Google."
The I/O audience was then shown a demonstration in which a user asked a question about Santa Cruz and the search engine answered back in "conversation," in addition to the presentation of results for the query. Google's Jessica Wright explained that the search engine uses data from the Knowledge Graph to produce results: "The Knowledge Graph knows that Santa Cruz is a place, and that this list of places are related to Santa Cruz".
See also 
- Singhal, Amit (May 16, 2012). "Introducing the Knowledge Graph: Things, Not Strings". Official Blog (of Google). Retrieved May 18, 2012.
- (registration required) Waters, Richard (May 16, 2012). "Google To Unveil Search Results Overhaul". Financial Times. Retrieved May 16, 2012.
- Staff (December 04, 2012). "Get smarter answers from the Knowledge Graph from Português to 日本語 to русский". Google. Retrieved December 04, 2012.
- Isidoro, Andrew (February 28, 2013). "Google’s Knowledge Graph: one step closer to the semantic web?". Econsultancy. Retrieved April 17, 2013.
- Jessica Lee (16). "OK Google: 'The End of Search as We Know It'". Search Engine Watch. Incisive Interactive Marketing LLC. Retrieved 20 May 2013.