A thermostat is part of a control system that senses the temperature and maintains a desired set point.
There are two different types of thermostats, both with their own benefits. There are programmable or smart thermostats:
Mechanical thermostats are the other type of thermostats you can buy. These thermostats are non-programmable, meaning you have to set the temperatures yourself.
This type of heating system uses a furnace or heat pump to warm the air and releases it through ductwork and vents. Cold air is pulled into the system where it is filtered and heated. The filter gets rid of any allergens and dust that could be brought in with the air. It is the only energy efficient heating system that is able to combine heating and cooling.