Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion.
Fire in its most common form can result in conflagration, which has the potential to cause physical damage
through burning.
Once ignited, a chain reaction must take place whereby fires can sustain their own heat by the further
release of heat energy in
the process of combustion and may propagate, provided there is a continuous supply of an oxidizer and fuel.
A flame is a mixture of reacting gases and solids emitting visible, infrared, and sometimes ultraviolet
light, the frequency
spectrum of which depends on the chemical composition of the burning material and intermediate reaction
products.