Why Are Candles Made of Wax?

Well, one might argue that by definition we call a light source made of wax a "candle" (as opposed to an oil lamp or match which has a similar purpose but uses different materials).

But what is special about the wax in a candle?

To understand the mechanisms of how a wax candle burns, read Why doesn't candle wax burn without a wick? first.

Wax has several unique properties that make it an ideal material to be used as the "fuel" of a candle. It is solid at room temperature, which makes it easier to handle than liquid lamp oil which must be kept in a container. It is also malleable and melts at a low temperature, making it easy to shape into whatever form you want it to be. The low melting point is very important because the energy required to melt the wax must be less than what is generated burning it, or the flame would not be self-sustaining. Natural sources of waxes (such as beeswax and paraffin) are commonly available for use in candles.