This update is massive, bringing with it a whole slew of changes. Notifications now appear on the lockscreen and are ranked by type who who sent them, priority and privacy notifications can be set for each application, high priority notifications, such as Amber alerts or Emergency notifications, will briefly pop up over an app your currently using, and you can customize how notifications behave with new Downtime and Ambient Display settings. That’s just a small preview of what this update brings. There’s a whole lot more.
If you haven’t received this update, your device should notify you shortly. However, you can manually grab the update by hitting Settings in the app tray, tap About Phone > System Updates, and then select, “Yes, I’m in.” The update will then begin to download, and after it’s downloaded, you can just hit the install button, and you should have Android 5.1 Lollipop in minutes.