You've probably heard of PageRank, Google's original secret sauce for organizing search results quickly and accurately. Now there's a new, artificial intelligence-powered search technology that's becoming increasingly important for Google: RankBrain. It's basically the company's solution for interpreting the some 15 percent of daily search queries that it's never seen before. RankBrain works by transforming words into "vectors," or mathematical entities, which Google's search engine can use to find similar words or phrases. That allows it to parse unusual search entries like, "What's the title of the consumer at the highest level of a food chain?" Over the past few months, RankBrain has become the third-most important signal for display search results, out of "hundreds" of signals currently in play, Google senior research scientist Greg Corrado told Bloomberg. It's also even better at sorting relevant search results than Google's own search engineers.