The evolution of web search engines offers an instructive example, showing how knowledge can be extracted from unstructured sources and refined over time into a structured, interconnected graph.

Here's an example of how Graph Search works, according to Curtiss. Say Curtiss is moving to New York City in a few weeks.

How exactly Graph Search works has remained a bit of a mystery, but recently Facebook’s Engineering blog gave a no-holds-barred look at what makes Graph Search’s gears turn.