This Mexican holiday is getting more and more popular in the US. We didn't grow up with this tradition, because our family is from Northern Mexico where the native traditions were absorbed by the Catholic Church. Therefore, I've had to learn about it myself.
While Halloween is on October 31st, Dia de los Muertos is November 1st & November 2nd.
The holiday focuses on gatherings of family and friends to pray for and
remember friends and family members who have died, and help support
their spiritual journey. Traditions connected with the holiday include building private altars called ofrendas, honoring the deceased using sugar skulls, marigolds,
and the favorite foods and beverages of the departed, and visiting
graves with these as gifts. Visitors also leave possessions of the
deceased at the graves.
A common symbol of the holiday is the skull (in Spanish calavera), which celebrants represent in masks, called calacas
(colloquial term for skeleton), and foods such as sugar or chocolate
skulls, which are inscribed with the name of the recipient on the
forehead. Sugar skulls as gifts can be given to both the living and the
dead. Other holiday foods include pan de muerto, a sweet egg bread made in various shapes from plain rounds to skulls and rabbits, often decorated with white frosting to look like twisted bones.
This is a well-done video for younger children:
https://www.facebook.com/delicias.prehispanicas/videos/514395435379092/
Another animated film is "The Book of Life". The trailer is here:
https://www.youtube.com/watch?v=NBw5YScs8iQ