Regular thermostats– You can adjust the temperature of your home (basically a control panel for your heating and air conditioning). A programmable thermostat lets you set the temperature and have the thermostat change the temperature depending on the time of day.
Smart thermostats- This thermostat is considered “smart” because it is learning your behavior. It allows you to control the temperature remotely and shows you energy consumption in real-time. They can even adjust themselves based on ambient conditions like humidity.
An example of a smart thermostat:
You can tell the thermostat turn off when you leave for work or to take the kids to school, and then turn back on ten minutes before you get home keeping the home at the perfect temperature you want to come home to. *Most smart thermostats show you how long it takes to make the change you’ve requested, so you can see how effective your climate control system really is, and it discourages people from turning a thermostat all the way down to try “cooling off the house faster” (which never works). Plus, you can manage many smart thermostats from your phone or a webapp. From the remote interface, you can always see how much you’re spending on heating or cooling costs, tweak the programming to you save money, and see the results immediately.
*Information provide by Lifehacker.com “What a smart thermostat does that mine can’t already”