What is in candles?

Depends on what type of Candle wax that is used, Such as Soy wax, Palm Wax, Paraffin, or Beeswax. It's the wax you prefer to use, then it's the Fragrance oil that's used to scent the candle, and then the dye block which is used to color the candle, and a wick that works for your candle so it may burn evenly. I'm a Candle Maker and I love making Soy Candles.