All throughout the regions of Mexico, El Dia de los Muertos is celebrated in different ways and with different traditions. In the states of Michoacan, Oaxaca and Yucatan all feature celebrations that involve processions to the cemetery where the living make ofrendas, or offerings of food to the departed on the night of the first of November. In Oaxaca, people believe that all the souls reside in Mitla (an ancient Mayan site) and therefore priests walk up and down the streets after the ceremonies reciting chants to make sure the souls have returned to Mitla.
In Yucatan after the ofrendas have been made, the graves of those who have been dead for three years are dug up, boxed, blessed and placed in a special building in the cemetery. In Michoacan only women are involved in the cemetery procession and ofrendas. The women sit on the graves in the cemeteries all night waiting for dawn when they will present the food to the departed souls.
There are a variety of reasons why the traditions range through the regions, included geographical differences but other differences range in the belief systems, the roles of men and women in society and communication difficulties.
In the United States we, too, celebrate the same holidays in different ways. Think about the differences between the North and the South or the cultural differences that exist in our own neighborhoods.