With the latest version of OS X, Siri makes its debut on Mac, with new capabilities designed just for the Mac operating system. And that's not the only way your Mac is smarter. Mac OS 10.12 Sierra helps you rediscover your best photos, shop faster and more conveniently online, and work more seamlessly between devices. It can also help free up valuable storage space. Now your Mac does even more for you, so you can do more with your Mac.