Google's OS finally bumped up a full integer to version 5.0. It been working on getting its new 'Material Design' aesthetic out in the world for months, and Lollipop is its culmination. One of Android's biggest failings up to date — including with KitKat — has been that its design language never felt unified, and with Material Design, it hopes to fix that.
The aesthetic is meant to look both flat and 3D, but the changes to Android's interface with Lollipop aren't all just visual — voice commands with 'OK Google' are more prominent now, and can be used when the screen is locked and off on some devices, and there are massive improvements to notifications.
In Lollipop you can see what notifications you've received and what's going on with your apps and contacts as soon as you pick it up, before you even unlock your device — and you can even respond to messages from the lockscreen.
The way you see notifications is changing as well — now rich, descriptive, and interactive notifiers will pop up on top of what you're doing without interrupting, so you can reject a call or read a message without quitting that game or whatever. Some of this functionality was present in KitKat, but it was halfbaked and inconsistent.
Android Lollipop is also getting a 'do not disturb' mode a la iOS, which Android KitKat and previous versions sorely lacked. Google says Lollipop is also better at connecting with Bluetooth and Wi-Fi.
Android Lollipop has some new security features as well, like the ability to set geographical 'safe zones' where your device won't require a PIN to unlock.
These phones will also have more RAM than existing phones with KitKat and other operating systems are capable of packing. Google says Android 5.0 is way more powerefficient over its predecessors. Android 5.0 Lollipop begins rolling out to devices in late October and early November.