Many modern thermostats are smart thermostats – Wi-Fi-connected devices that are part of the Internet of Things (IoT). Smart devices (such as a smart thermostat) communicate with other connected devices (like a cellphone) and can be controlled remotely, allowing you to make changes and maintain control from your connected device. For example, you can control the unit’s temperature from your cellphone when the weather changes, or you simply want to save money during certain times of the day. Smart thermostats are compatible with most HVAC systems and can be installed easily and quickly.