We've all seen the progression of different CAPTCHA systems for identifying that yes, you are indeed a human visiting a website. Google's reCAPTCHA has been the most innovative in the past few years, getting all the way to a point where you just check a box and move on. Now, the reCAPTCHA system is ready to disappear from sight entirely while still doing its job of preventing bots from compromising sites.
Every time one of the millions of daily reCAPTCHA interactions occurs it sends data to Google to be able to better understand the difference in behaviors between people and bots when they attempted to access websites. Now that data has finally paid off, and Google feels it has enough information to be able to identify if you're a real person visiting a site, or a bot attempting to compromise it, without any explicit actions on your part.
Same great security, with fewer user interactions.
The end result is the new reCAPTCHA system that simply lets you seamlessly continue using a website, passing a security check without even knowing it. This is incredibly important especially on mobile websites, where reCAPTCHA won't have to take up precious screen real estate on a checkout or sign-up page where user flow is critical.
From our perspective as users of popular websites, there's nothing new to do here fortunately. Website admins can learn more about the new reCAPTCHA from Google, and integrate it into their own sites. After they do so, their users will see fewer roadblocks to using the site while still keeping the same level of great security.