Intelligent thermostat. It has built in motion detection sensors and a little SoC which allows the device to adjust the temperature in the room/house according to what it perceives as your habbits. So there's very little fiddling with it after the initial setup.
Basically, just like a TV remote, this is a device for very lazy people. But we like it nevertheless.
Back on topic, a company which produces thermostats can't really count on too much repeat business. So Google subsidiary Nest decided to regularly launch new and improved versions of their intelligent thermostat in the hope that you'll end up discarding the "old" but perfectly functioning one you already have. And buy the new. Buy.
We're a gadget focused site, so let's write up the description of the new features.
1. the screen is bigger and it has more pixels
2. the display turns on when the device detects motion in the room
3. the device monitors the furnace and prevents it from overheating.
So, there's at least one useful feature. No, make that two: the new generation reduced the price of the previous one. The 3rd generation Nest costs $249, which means that the 2nd generation now costs $199, which is a bargain.
And since we haven't used the words enough in this article, let us all repeat together: intelligent thermostat. There is a fancy video below that explains more.