Steam is a form of water.
Steam is water in the gas phase , which is formed when water boils . Steam is invisible ; however , `` steam '' often refers to wet steam , the visible mist or aerosol of water droplets formed as this water vapour condenses . Steam explosion . A steam explosion sprays steam and boiling-hot water and the hot medium that heated it in all directions ( if not otherwise confined , e.g. by the walls of a container ) , creating a danger of scalding and burning . Water . Water strictly refers to the liquid state of that substance , that prevails at standard ambient temperature and pressure ; but it often refers also to its solid state ( ice ) or its gaseous state ( steam or water vapor ) .