Halloween is a holiday celebrated on October 31. By tradition, Halloween begins after sunset. Long ago, people believed that witches gathered together and ghosts roamed the world on Halloween. Today, most people no longer believe in ghosts and witches. But these supernatural beings are still a part of Halloween.
Popular Halloween costumes include vampires (creatures that drink blood), ghosts (spirits of the dead) and werewolves (people that turn into wolves when the moon is full).
Trick or Treating is a modern Halloween custom where children go from house to house dressed in costume, asking for treats like candy or toys. If they don't get any treats, they might play a trick (mischief or prank) on the owners of the house.
The tradition of the Jack o' Lantern comes from a folktale about a man named Jack who tricked the devil and had to wander the Earth with a lantern. The Jack o' Lantern is made by placing a candle inside a hollowed-out pumpkin, which is carved to look like a face.
One of the oldest Halloween traditions comes from the ancient Celts， who lived in western and central Europe long ago. The Celts celebrated a holiday called Samhain on October 31. After sunset that day， people believed that spirits of the dead would rise and walk the earth. The Celts made offerings of food and drink to keep the spirits away.
Beginning about 2，000 years ago， the Roman Empire conquered many Celtic peoples. But Celtic traditions， including Samhain， remained strong in areas such as Ireland and Scotland， even after the Roman conquest.
The Roman Catholic Church tried to replace Samhain in 835 with All Saints' Day， a day to honor saints of the Church. The eve of All Saints' Day is October 31. It is called Allhallows or Hallowmas by the Church.