No steam references entropy or distribution of the molecules in the air. Concentrated water molecules visible as myst produced from hot water is steam. The water molecules evenly dispersed in the air is humidity.
>Concentrated water molecules visible as myst produced from hot water is steam.
Steam/water vapor/humidity is gas phase H2O and is transparent. Water droplets in air is often referred to as 'steam' or 'wet steam' but is liquid phase H2O suspended in air. If it mattered in context I assume it would be clearly stated as gas rather than liquid mist.
I doubt anyone would call the component of air that is 'humidity' by the word 'steam' but it seems it would be correct [1]. I am used to the term 'water vapor' for that gas phase H2O though.
