Google has launched the Knowledge Graph, which it says will help you discover new information quickly and easily, according to the Official Google Blog.
Think of it as Google + Wikipedia + Wolfram Alpha + Bing.
Take a query like [taj mahal]. For more than four decades, search has essentially been about matching keywords to queries. To a search engine, the words [taj mahal] have been just that — two words.
So Google has been working on an intelligent model — a “graph” — that understands real-world entities and their relationships to one another: things, not text strings. The Knowledge Graph enables you to search for things, people or places that Google knows about — landmarks, celebrities, cities, sports teams, buildings, geographical features, movies, celestial objects, works of art and more — and instantly get information that’s relevant to your query.