Halloween has its roots in the Celtic festival of Samhain a harvest festival dedicated to Celtic pagan spirits. Celtic Pagans still consider Halloween a religious holiday to this day. However, most people around the world view Halloween as a non-religious holiday dedicated to imaginary spooks and merrymaking. It is this perception of Halloween as a non-religious holiday that has helped Halloween spread around the world. Halloween is widely associated with costume parties, ghosts and demons, trick-or-treating, candy, jack-o'-lanterns, pranks and the macabre.
Halloween is the most global holiday. This is because it is one of the few major holidays not associated with religion. Despite its global popularity, Halloween is not a official national holiday in any country.