Unlike Halloween, which is known for parties, dressing up and trick or treating for candy, Dia de los Muertos is about honoring our dearly departed. This is done by visiting our loved ones at cemetaries, cleaning and caring for the gravesite and praying as we visit the decedant. 
Either at an art installation, gravesite or in one's home, an altar in honor of the decedant is built. The altar contains marigolds (a type of flower), a photo of one's dearly departed, their favorite food and beverage and trinkets representing their passion/interest in life (i.e. CDs for music lovers, dancing calaveras (skeletons) for the mamboer in us, books, crochet needles, etc.). Family and friends then pray at the altar and pay their respects.
Altars can be very orante and elaborate or very simple and understated. Either way, visitors leave with a very definite sense of what type of person the decedant was and how they embraced life. It's a wonderul way to share aspects of a departed loved one, with younger family members who never had an opportunity to meet or know them, in a rich, colorful and festive environment. Many installations will remain on view through November 5th, if you have an opportunity visit one.
More photos here.
