Sony has started rolling out the Android 5.0 Lollipop update for the Sony Xperia Z1, Sony Xperia Z1 Compact and the Sony Xperia Z Ultra. The update brings Android 5.0.2 along with the 14.5.A.0.242 build number, and is currently rolling out only in certain regions, so it may be awhile before it is available for your device.
With Android Lollipop, your Xperia handset will be treated to the new Material Design, Lock Screen notifications, the new 64-bit ART runtime compiler that will open apps faster, new "Recent Apps" screen, Project Volta for extended battery life, and more.
Since the update is rather larger in size, it is recommended that your connect to Wi-Fi to avoid unnecessary data charges. It is also recommended that you're ensure your battery is appropriately (at least 50%) charged before installing the update.
Check out some screenshots of the Android Lollipop update below.
source - XperiaBlog