A candle functions as a solid fuel source designed for the controlled exothermic combustion process, yielding visible light and heat. The structure typically comprises a solid fuel material, such as paraffin wax, tallow, or beeswax, and a porous wick. When a flame is introduced, the heat energy causes the solid fuel to melt and subsequently vaporize. The gaseous fuel vapors are then drawn up the wick through capillary action, where they mix with oxygen from the ambient environment. This mixture undergoes rapid combustion, a chemical reaction that releases energy in the form of light (photons) and thermal energy. The rate and efficiency of the combustion are dependent upon the vaporization rate of the fuel, the thermal conductivity of the wick, and the steady supply of oxygen, making it a relatively low-energy, open-flame heat and illumination technology.