A candle is an ignitable wick embedded in wax, or another flammable solid substance such as tallow, that provides light, and in some cases, a fragrance. A candle can also provide heat or a method of keeping time. Candles have been used for over two millennia around the world, and were a significant form of indoor lighting until the invention of other types of light sources. Although electric light has largely made candle use nonessential for illumination, candles are still commonly used for functional, symbolic and aesthetic purposes and in specific cultural and religious settings.

Early candles may be made of beeswax, but these candles were expensive and their use was limited to the elite and the churches. Tallow was a cheaper but a less aesthetically pleasing alternative. A variety of different materials have been developed in the modern era for making candles, including paraffin wax, which together with efficient production techniques, made candles affordable for the masses. Various devices can be used to hold candles, such as candlesticks, or candelabras, chandeliers, lanterns and sconces. A person who makes candles is traditionally known as a chandler.^[1]

 

The combustion of the candle proceeds in self-sustaining manner. As the wick of candle is lit, the heat melts and ignites a small amount of solid fuel (the wax), which vaporizes and combines with oxygen in the air to form a flame. The flame then melts the top of the mass of solid fuel, which moves upward through the wick via capillary action to be continually burnt, thereby maintaining a constant flame. The candle shortens as the solid fuel is consumed, so does the wick. Wicks of pre-19th century candles required regular trimming with scissors or "snuffers" to promote steady burning and prevent smoking. In modern candles, the wick is constructed so that it curves over as it burns, and the end of the wick gets trimmed by itself through incineration by fire.^[2]

for more info go to https://en.wikipedia.org/wiki/Candle