Elements of fire:
Heat: Heat is required to elevate the temperature of a material to its ignition point
Fuel: The fuel for a fire may be a solid, liquid, or gas. The type and quantity of the fuel will determine which method should be used to extinguish the fire
Oxygen: Most fires will burn vigorously in any atmosphere of at least 20% oxygen. Without oxygen, most fuels could be heated until entirely vaporized, yet would not burn.
These three elements, called the fire triangle, create a chemical exothermic reaction, which is fire.