Fire is the rapid oxidation of a substance, often with the evolution of heat and light in varying degrees of intensities.

Misconception: fire burns the actual chair, piece of wood or fuel. It is, actually, the gasses given off by an object that burns. Heat causes objects to give off these flammable gasses. When the gasses reach their ignition temperature you see the light given off during the oxidation process we know as fire. The fire itself, generates more heat to the object, thus an endless cycle begins, until all of the gasses have been exhausted from the object, leaving carbon particles or solid ash (unburned carbon).

The concentration of gasses around the wick are too high to allow ignition and there is insufficient oxygen to support combustion. As the gasses spread away from the wick they ignite due to the already present heat being generated by the fire.

The Fire Tetrahedron (shown below) is very similar to the familiar Fire Triangle, the difference is the Fire Triangle did not represent a previously unrecognized critical component: Chemical Chain Reaction. The Fire Tetrahedron represents all the known components of fire:   

Fuel, Oxygen, Heat, and a Chemical Chain Reaction.

Extinguishing a fire is based upon removing or separating any one of these components.

The most common component to be removed is heat, most easily eliminated by using water which absorbs heat extremely well.  Without the objects being exposed to heat there can be no flammable gasses given off to burn.   

The third component, oxygen, is usually the hardest to remove.  Oxygen removal can be accomplished with a Carbon Dioxide extinguisher. 

Finally, the chemical chain reaction can be considered the reaction of the reducing agent (fuel) with the oxidizing agent (oxygen).  An example, of an extinguishing method by disrupting the chemical chain reaction, is the Halogenated fire extinguishers.