A smart thermostat is a type of IoT device designed to optimize heating and cooling in homes or buildings. This device uses sensors and internet connectivity to monitor environmental conditions and user preferences. Smart thermostats can be programmed, adjusted remotely via mobile applications, and even learn user patterns to create energy-efficient settings automatically. By integrating with other smart home systems, these devices can help reduce energy consumption, lower utility costs, and promote comfort, making them a popular choice among homeowners and businesses.