What is the most suitable indoor humidity?

If it is autumn and winter, the indoor temperature should be kept between 18-25 degrees Celsius and the humidity should be controlled between 30-80%. But in summer, the indoor temperature should be controlled between 23℃ and 28℃, and the humidity should be controlled between 30% and 60%. The humidity of the air, or a physical quantity indicating how much water vapor is contained in the air, is called humidity. The mass of water vapor contained in air per unit volume is called absolute humidity. Because the density of water vapor is difficult to measure directly, it is usually expressed by the pressure of water vapor. The absolute humidity of air does not determine the speed of water vapor on the ground and people's feeling of humidity. People call the absolute humidity of air at a certain temperature and the percentage of saturated air pressure at the same temperature as relative humidity.