Day of the Dead in Mexico represents a mixture of Christian devotion and Pre-Hispanic traditions and beliefs. As a result of this mixture, the celebration comes to life as an unique Mexican tradition including an altar and offerings dedicated to the deceased.
The altar includes four main elements of nature — earth, wind, water, and fire.
Earth is represented by crop: The Mexicans believe the souls are fed by the aroma of food.
Wind is represented by a moving object: Tissue paper is commonly used to represent wind.
Water is placed in a container for the soul to quench its thirst after the long journey to the altar.
Fire is represented by a wax candle: Each lit candle represents a soul, and an extra one is placed for the forgotten soul. http://www.dayofthedead.com/