my understanding of a demon is that essentialy it is a spirit or supernatural creature/being that has ill intentions towards and preys apon people.
but not a demon of hell
demons are not solely scourced from hell as demons apear through mythology long before the christian envisionment of hell.
it is more of a discription of wheither or not you should be wary of it as the are seen to be more hosstile and have hidden agendas compare to a
disgruntled ghost.
an example is that some fairies in myth are refered to be demons or demonic in nature becuase of their motives and actions.
[edit on 21-11-2009 by RokNinja]