Google Now automatically creates and presents a series of “cards” that try to organize your life by presenting information Google thinks you’ll need at that particular moment - based on the information it’s collected via how you use various Google services - in a context that it hopes you’ll find useful.
Google Now aggregates the information Google already collects about you on a daily basis: accessing your email, your calendar, your contacts, your text messages, your location, your shopping habits, your payment history, as well as your choices in music, movies and books. It can even scan your photos and automatically identify them based on their subject, not just the file name (in the Google I/O demo, Google Now correctly found a picture of the Great Pyramid). About the only aspect of your online life that Google hasn’t apparently assimilated yet is your opinions expressed on Google+. But that’s undoubtedly coming.
Google already knows where you live, for example, and constantly plots out the time it will take to return home. Google even knows your favorite routes to work and can suggest alternatives based on congestion. And it will figure out your favorite sports teams by the number of times you ask about them, without you ever having to explicitly identify them. Google’s recommendation engine, meanwhile, uses the information to suggest new content to purchase.