"Monday, Google announced the availability of a new “Device Protection” capability on Android 5.1 that builds on its effort to make Android smartphones a little more business- friendly. The feature is similar to the Activation Lock on the Apple iPhone in the sense that it prevents unauthorized users from using a lost or stolen Android smartphone.
According to Google, with Device Protection, a lost or stolen device will remain locked until the legitimate user signs into the device via their Google account. The device will remain locked even if it has been returned to its original factory settings, Google said. The Device Protection feature will be available on most Android 5.1 smartphones as well as on Nexus 6 and Nexus 9 handsets, the company said.
The lock functionality should help relieve at least some of the concerns that IT administrators might have in allowing employees to use Android devices to access and store business applications and data. For businesses, it reduces the danger of data leaks and data theft resulting from lost or stolen Android devices."
It makes it harder for thieves to wipe a stolen device, making it essentially useless except for parts. It’s unclear to me how exactly it works, since I haven’t had a chance to play around with it myself, but it prevents the google account on the device from being completely deleted AND requires that google account to log in with its password in order to fully boot the device and complete the wipe.