El Día de los Muertos, also known as the Day of the Dead or All Souls' Day, is a holiday celebrated in Mexico and by Latin Americans living in the United States and Canada. The Day of the Dead festival has its origins in a pre-Hispanic Aztec belief that the dead return to Earth one day each year to visit their loved ones.

The holiday focuses on gatherings of family and friends to pray for and remember friends and family members who have died. The celebration occurs on November 1st and 2nd in connection with the Catholic holiday of All Saints' Day which occurs on November 1st and All Souls' Day which occurs on November 2nd.

Traditions include building private altars honoring the deceased, using sugar skulls, marigolds, and the favorite foods and beverages of the departed, and visiting graves with these as gifts.

Scholars trace the origins of the modern holiday to indigenous observances dating back thousands of years, and to an Aztec festival dedicated to a goddess called Mictecacihuatl.

Similar holidays are celebrated in many parts of the world; for example, it's a public holiday (Dia de Finados) in Brazil, where many Brazilians celebrate by visiting cemeteries and churches. In Spain, there are festivals and parades, and at the end of the day, people gather at cemeteries and pray for their loved ones who have died. 

Similar observances occur elsewhere in Europe and in the Philippines, and similarly-themed celebrations appear in many Asian and African cultures.