Steam

Steam is the name given to water when it is a gas. Steam is a form of water vapour. Steam is sometimes seen as a string of cloudy translucent mist. But, that is only the result of the steam condensing on the surface of dust in the air, which means the steam that you touch would not be very hot. The steam that is really 100 degrees Celsius is invisible.

When the pressure of the atmosphere is 1013 mbar (this is about the average pressure for a place which is at sea level), water will boil (turn into steam) at 100 degrees Celsius.

100 degrees Celsius is the same temperature as 212 degrees Fahrenheit, 80 degrees Réaumur and 373.15 Kelvin.