Halloween has its origins in Celtic traditions celebrating Samhain. The holiday also has Christian influences and is associated with themes of orange and black, horror, and disguise. Traditionally, jack-o-lanterns were carved to guide spirits and scare away bad ones, while costumes and masks were also worn for protection. Modern Halloween traditions include trick-or-treating, eating foods like candy and pumpkin treats, and participating in activities like costume parties, haunted houses, and telling scary stories.