The Nest Learning Thermostat is a device that learns your routines and programmes itself to help you save energy and money. It uses a full-color display to show you the temperature you've set and the temperature you have now. The Nest Learning Thermostat also learns how to make you comfortable. This smart home tool makes small adjustments to your daily schedule. Instead of cranking the heat or air conditioning way up, that helps you save energy and money. If Nest can't get your house to the temperature you've set, it will tell you why. More look here.