In
fairy tales, Trolls live in the deep forests or in caves
in the mountains, far away from the people. The Trolls also
tend to be a bit stupid, so the hero of the story can easily
outsmart them (and save the princess, the kingdom, or just
himself).
One
way of getting rid of a Troll is exposing it to sunlight.
Daylight will make the Troll explode, BANG, and gone is
the problem. Alternatively, the sun rays will turn the Troll
into stone. Trolls often guard a dazzling treasure which
the hero can bring back to his family after defeating the
Trolls.