The factors that must be present in combination for a fire to continue to burn are Fuel, Heat and Oxygen. Isolating or removing any of these factors from the combination will extinguish the fire. There are three basic ways of achieving this. 

*Starving: Starving is the method of extinguishing the fire by removing the fuel in the vicinity of fire. 

*Smothering: Smothering is the method of extinguishing the fire by removing the oxygen with blanketing fire with foam, sand etc. 

*Cooling: Cooling is the process of extinguishing the fire by using water to lower the temperature.