h % on scale

soccerella

I have a scale that monitors fat% and h% in addition to my weight. I assume the h% thing stands for hydration percentage

I dont put alot of stock into these type of scales and dont pay much attention to the fat% or h%, but I was curious to see if it has changed at all given that I have been drinking a whole lot more water in the past few weeks than I normally do. The h% is still at 55.7% and is always right around 55%

so my question is, is it actually measuring hydration%, how /what is it measuring to do that, and is there an optimal number that you should have? Like I said, I dont really pay much attention to this number on my scale, but would like to know what it really means