What is Knowledge Graph?
The Knowledge Graph is Google’s system for organising information about millions of well-known entities: people, places, and organisations, to build a map of how information is interconnected. It’s a knowledge base used by Google to enhance its search results with the use of human language technology (e.g. entity recognition and linking) and the semantic web (graphs of linked data).
The Knowledge Graph is used behind the scenes to help Google improve its search relevancy, but also to enhance search presentation: When a search query contains a notable entity—such as a well-known brand or a famous person—a Knowledge Panel, which is a type of rich answer, is displayed on the results page, populated with instant answers and links to related content.