The radiators in your home function as room heating. Radiators heat the air in the room, which then circulates and provides an even temperature. Heat rises, which is why it can feel warmer at ceiling height than at floor level – even if the room is at the desired temperature.
The radiators are controlled by thermostats, which measure the temperature in the room and regulate the heat accordingly. When the desired temperature is reached, the radiator automatically turns off the heat.