Combustion can only occur when the 4 most essential components are present—an oxidizer (i.e. oxygen), heat energy to start ignition, fuel and the forth being that the combustion process must be a self-sustaining chain reaction where the fuel and oxidizer must interact(a diagram can be inserted to better illustrate this point). If any one of these components is not present, the fire will extinguish.

Flaming fire

A flaming fire is identified by the flame. It is the production of gaseous reaction products with the evolution of heat and light. One prominent characteristic of flaming fires is that there has to be either a gas or vapor burning. The flame is a totally gaseous reaction. Flaming fires are most often the product of the combustion of solid fuels and liquid fuels can only produce flaming fires. Flaming fires are oxidized, gaining a fresh supply of oxygen through convection currents, where the plume of hot gases rise since it is less dense then the ambient air in the room. Generally, when the concentration of oxygen in the room falls below 15%, the combustion rate of ordinary combustibles begins to decrease. The lowest oxygen limit that will eventually extinguish a flame varies from fuel to fuel and the temperature of the combustion going on. The greater the temperature of the combustion, the greater the tendency of the combustion to keep on going under lower oxygen concentration.