When the water boils, steam is generated in the kettle. Why is this happening?

When boiling, water gradually passes from a liquid into a gaseous form, this is due to the fact that when heated, the distance between the molecules of the liquid increases significantly, the formed vapor immediately rises upward, since it is lighter than air. In a kettle, steam is formed in the entire volume of boiling liquid, and we observe how it comes out of the kettle, however, we do not see the steam that is necessarily present in the air around us, it is formed mainly from the evaporation of water in reservoirs.