Fire is a chemical reaction.
Fires start when a flammable and/or a combustible material with an adequate supply of oxygen is subjected to enough heat and is able to sustain a chain reaction. Fire cannot exist without all of these elements being in place.
A fire needs oxygen and some kind of fuel such as wood, candle wax, or gasoline.
So the fire is not object, but it is a combination of parts and combining in a reaction, while the process is running, the fire is exist.