Many Americans, especially children, are celebrating the holiday Halloween Tuesday by dressing in costumes and going door-to-door to collect candy.
Halloween takes its name from "All Hallows Eve," the day before the Christian observance of "All Saints Day" on November 1. But its origin dates back 2000 years and comes from a pagan holiday that honored the dead on the last day of the Celtic calendar on October 31.
Halloween gained wide popularity in the United States and other Western parts of the world in the 20th century.
And now, on the night of October 31, it has become tradition for millions of children to dress up as fun or scary characters and shout "Trick-or-Treat" to collect candy. The day is also marked by pumpkin carvings, parties and parades.
Some Christians still consider Halloween a pagan holiday and refuse to celebrate it.
The U.S. film industry uses Halloween to make huge profits by releasing scary movies leading up to October 31. The frightening new film Saw III currently tops ticket sales at American cinemas.