The answer to 'what does thermostat do' is that a thermostat is a device that controls the temperature in a home or building. It monitors the temperature and turns the heating or cooling system on and off to maintain the desired temperature set by the user.
Thermostats come in a variety of types, from basic manual models to more advanced programmable and smart thermostats. They play a crucial role in home comfort and energy efficiency by automatically adjusting the HVAC system to keep the temperature at the preferred level. Thermostats help homeowners save money on their energy bills by preventing the HVAC system from running unnecessarily.