One is the themometer, and the other is the humity gauge. The humity gauge measures the humidity. Humidity is the water vaper. Water vaper is hard to see unless there is a lot in the air, then it is seen in the form of clouds. You can feel water vapor when the humidity is high.
Humidity is how much water vapor there is in the air.
We think water vapor is neat. This is our weather station. This the weather vane. The weather vane shows you which way the wind is coming from.