Absolute humidity indicates the actual amount of water vapor in the air (g/m³) and remains constant regardless of the temperature. Relative humidity, on the other hand, changes with temperature and can therefore be deceptive - warm air can absorb more moisture than cold air, so a high value does not always mean that the air is actually humid.
The dew point is the temperature at which the air is completely saturated with moisture and condensation sets in - in other words, water precipitates out of the air. The closer the room temperature is to the dew point, the higher the risk of mold and moisture damage.
Climatus-S uses the dew point as a reference value to activate ventilation or dehumidification only when moisture transport can actually take place. This prevents humid outside air from entering the interior or unnecessary energy being wasted on ineffective control.