The tradition of Halloween celebrations return every October 31st. Nowadays those who enjoy the celebrations the most are the children. Halloween is an opportunity to dress up in fancy dress and call on the neighbors trick or treating. Some families go out of their way to decorate their house and front yard in a ghostly and creepie Halloween theme.

Halloween is a traditional Celtic festival, and has survived through the ages most strongly in the Celtic communities in Ireland, Scotland and Wales. From there, with emigration, Halloween has spread around the world, most notably to America. In recent years, the spread of popular American culture has introduced a further expansion of interest in Halloween to fresh places, such as Asia and Western Europe.

The first Celtic customs were pagan festivals linked to the seasonal changes with the onset of winter. The ancients saw it as a time when the living could contact the dead, and magic things could happen. The early Christian church, as with many pagan festivals, absorbed these customs into the Christian calendar. All Saints Day, also known as All Hallows Day, was assigned to November 1st. All Hallows Evening, the night of October 31st, became known as Hallow E'en, later just Halloween, and the time for the ancient celebrations.

Halloween was a community festival, often around a warming fire and with lots of fun games. The apple harvest was in full swing, and games such as trying to eat an apple on a string or floating in a barrel of water without using your hands, were popular. Children would go from door to door to gather fruit, nuts and other goodies for the festivities, which was the origin of the "treating" visits of today. In most places, especially in Scotland, the children would sing or put on a performance in return for the treats they collected. Today the treats collected are more likely to be candies and sweets, and sometimes money.

Early on, Halloween "tricks" were secretive and often clever pranks played on some adults by children. The mischievous spirits that were said to be abroad on Halloween were blamed. This activity was especially popular in Ireland. A long time ago, tricks and treating combined into an ultimatum: give a treat or become the victim of a trick. This undesirable habit led to such unpleasantness as tossing eggs at houses and soaping windows, and more serious vandalism. Nowadays such unruly behavior is not often seen.

Halloween party venues are often decorated with a haunted house theme. To the pleasure of children, Halloween menu items often include tomato soup described as vampire soup, spaghetti renamed as cemetery worms, and the always popular long cookies tipped with sliced almonds and described as witches' fingers. Pumpkins are made into carved jack-o-lanterns, and the pumpkin flesh used for pumpkin dishes, such as the pumpkin pie that is traditionally a feature of Halloween menus.

For the last few years, the magic and wizards themes of the popular Harry Potter books have added fresh ideas to Halloween fancy dress and decorations for children's Halloween parties.

Halloween costume parties have also become popular events for adults as well in recent years. They are a great excuse to dress up and have fun. It seems the trend today is for any costume to be acceptable, not necessarily just the traditional witches, vampires and ghosts of Halloween. Costume design inspirations are now drawn from many sources, such as recent movies and television series. Some costumes are just witty, such as the seasonally appropriate theme of a "leaf blower", consisting just of a leaf suspended from the brim of a cap where it can be blown.