How do they celebarte Halloween?

Please provide more context! "They" could refer to a lot of different groups of people.

For example, do you mean:

* Children? They typically go trick-or-treating, wear costumes, and attend Halloween parties.

* Adults? They might throw costume parties, decorate their homes, go to haunted houses, or carve pumpkins.

* A specific culture? Halloween traditions vary widely around the world.

* A specific region? For example, Halloween celebrations in the United States differ from those in the United Kingdom.

Tell me more about who you're interested in and I can give you a more specific answer!