The boiled water (assuming even heating throughout) is what reaches boiling temperature, 100°C, which is the entire pot. Additional energy applied to the pot/water after that point turns at some rate the already-at-100°C-boiled-water into water vapor/gas/steam. If you stop heating before all the already-at-100°C-boiled-water disappear, you have left what is or will have been "boiled water".