Boiling water is the process of heating water until it reaches its boiling point, which is typically 100 degrees Celsius (212 degrees Fahrenheit) at sea level. At this temperature, water molecules gain enough energy to transition from a liquid state to a gaseous state, forming steam. When water boils, bubbles form and rise to the surface, indicating that the water is actively changing. Boiling is commonly used in cooking, such as for making pasta or sterilizing utensils. It is also a method for purifying water, as the high temperature can kill harmful microorganisms.