Fire is the observable effect of the procedure for combustion - a special kind of chemical reaction. It happens between oxygen in the air and a few types of fuel. The products from the chemical response are totally distinct from the startintg material. The fuel should be heated to its ignition temperature for combustion to happen. The response will keep going so long as there's enough heat, fuel and oxygen. Combustion is when fuel reacts with oxygen to discharge heat energy. Combustion may be slow or fast, contingent upon the quantity of oxygen available. Combustion that leads to a fire is very quick and is called burning. 

Throughout the chemical response that creates fire, fuel is heated to the extent that it discharges gases from its surface. When these gases are hot enough, the substances in the gases break apart, as well as fragments of substances rejoin with oxygen from the atmosphere to make new molecules - water molecules and CO2 molecules - along with other products if burning is not complete. Heat generated by the reaction is what keeps the fire burning. The heat of the fire will keep the fuel at ignition temperature. The fire ignites the gases being emitted, and the fire spreads as well. 

So long as there is enough fuel as well as oxygen, the fire will continue burning. During the entire combustion, the burning fuel may produce only water and CO2. For this to occur, there needs to be adequate oxygen to combine fully with the fuel gas. A lot of us use methane gas, generally known as natural gas, at home for cooking. When the gas is heated as well as if there's sufficient oxygen in the environment, the substances may break apart and reform completely as water and CO2. If there isn't sufficient oxygen available during a chemical response, imperfect combustion happens, and products like carbon, carbon monoxide, water, and CO2 are produced.

Barak Bacharach, SkySaver Content Manager