The ritual is celebrated in Mexico and certain parts of the United States.
Celebrations are held each year in various areas and although the ritual has since been merged with Catholic theology, it still maintains the basic principles of the Aztec ritual, such as the use of skulls.
Today, people don wooden skull masks called calacas and dance in honor of their deceased relatives. The wooden skulls are also placed on altars that are dedicated to the dead. Sugar skulls, made with the names of the dead person on the forehead, are eaten by a relative or friend, according to Mary J. Adrade, who has written three books on the ritual.
The Aztecs and other Meso-American civilizations kept skulls as trophies and displayed them during the ritual. The skulls were used to symbolize death and rebirth.
The skulls were used to honor the dead, whom the Aztecs and other Meso-American civilizations believed came back to visit during the month long ritual.
Unlike the Spaniards, who viewed death as the end of life, the natives viewed it as the continuation of life. Instead of fearing death, they embraced it. To them, life was a dream and only in death did they become truly awake.
"The pre-Hispanic people honored duality as being dynamic," said Christina Gonzalez, senior lecturer on Hispanic issues at Arizona State University. "They didn't separate death from pain, wealth from poverty like they did in Western cultures."
However, the Spaniards considered the ritual to be sacrilegious. They perceived the indigenous people to be barbaric and pagan.
In their attempts to convert them to Catholicism, the Spaniards tried to kill the ritual.
But like the old Aztec spirits, the ritual refused to die.
To make the ritual more Christian, the Spaniards moved it so it coincided with All Saints' Day and All Souls' Day (Nov. 1 and 2), which is when it is celebrated today.
Previously it fell on the ninth month of the Aztec Solar Calendar, approximately the beginning of August, and was celebrated for the entire month. Festivities were presided over by the goddess Mictecacihuatl. The goddess, known as "Lady of the Dead," was believed to have died at birth, Andrade said.
Today, Day of the Dead is celebrated in Mexico and in certain parts of the United States and Central America.
"It's celebrated different depending on where you go," Gonzalez said.