Candles operate through combustion, a process involving heat, fuel, and oxygen. The wick, usually made from cotton or other fibrous materials, functions as the fuel delivery system, absorbing the melted wax and carrying it to the flame. The primary fuel source for candles is wax, with common types including paraffin, soy, beeswax, and palm wax. Upon lighting a candle, the flame's heat melts the wax close to the wick, which is then drawn up the wick through capillary action. As the liquid wax moves upward, it heats further, vaporizing into a flammable gas. When this vaporized wax combines with oxygen in the air, it combusts, generating the visible flame. The flame's heat continues to melt additional wax, sustaining the burning process.