Android TV is a new variant of Google's mobile OS aimed at TVs, game consoles and set top boxes. The successor to the ill-fated Google TV, Android TV brings a new, streamlined user interface to TVs and set top boxes, designed to put content front and center. It's based upon Android 5.0 Lollipop, which of course also runs on phones, tablets and cars via Android Auto.
With Android TV you'll be able to watch content from a variety of providers such as Google Play, Netflix and YouTube as well as play a host of Android games. Google's voice search will help you get to what you want with ease and with Google Cast built in all the apps that support Chromecast will be able to interact with Android TV. The interface is primarily controlled through included TV-style remotes, but can also be used with a Bluetooth game controller or a remote app on your Android phone. App developers can target Android TV specifically when developing, and design apps and games with an interface that's specifically tailored to be viewed from a distance and controlled with a remote or game controller.
Sony has committed to putting Android TV on its complete 2015 TV lineup, with Sharp and TPVision committing to their 2015 TV lineup carrying the software. Android TV, and the first hardware to go with it, were announced at Google I/O 2014. Since then Google also released the Nexus Player, its first consumer-facing hardware to run Android TV, and other manufacturers have announced small set top box style units with the software on board.