Android Lollipop is the fifth major version of the Android mobile operating system developed by Google and the 12th version of Android, spanning versions between 5.0 and 5.1.1.
Unveiled on June 25, 2014 at the Google I/O 2014 conference, it became available through official over-the-air (OTA) updates on November 12, 2014, for select devices that run distributions of Android serviced by Google (such as Nexus and Google Play edition devices). Its source code was made available on November 3, 2014. It is the fifth major update and the twelfth version of Android.
One of the most prominent changes in the Lollipop release is a redesigned user interface built around a design language known as Material Design, which was made to retain a paper-like feel to the interface.
Other changes include improvements to the notifications, which can be accessed from the lockscreen and displayed within applications as top-of-the-screen banners. Google also made internal changes to the platform, with the Android Runtime (ART) officially replacing Dalvik for improved application performance, and with changes intended to improve and optimize battery usage.
Android Lollipop was succeeded by Android Marshmallow, which was released in October 2015.