I thought ghosts were spirits that aren't sure if they go down or up. Ghost probably come from deamons. Or ghost are from purgatory. Maybe ghosts... I have heard a lot of a lot of diverse answers. What are ghosts really!

Yes and no.
When somebody says the word "ghost", by using that word they are typically referring to a human spirit.
Even though spirit can refer to both demonic and human spirits... the two individually mean very different things.

The belief in ghosts as human spirits has been around for thousands of years... as that of demons. So, in the wording of these spirits, yes there is a difference.

I also answer "no" because I believe there to be ample evidence to the contrary. I do believe "ghosts" to actually be demons.
I do not subscribe to the idea that the human spirit remains on earth after death. I believe the bible teaches this doctrine very directly.

Now as to what exactly a demon is, there is some division.
MOST people believe they are fallen spirits or angels from a heavenly rebellion... but there are other possibilities.
There is good chance they were a pre-adamic race that once populated the earth. While I cannot put my whole belief in this explanation there are great theories out there that can be supported to a degree.

Regardless of who they are or once were, the most important aspect of demons is how to deal with them now, as they are... and there is where biblical information comes in.
If a ghost manifests and claims to once be human... most of the world takes it at face value. However, I know of many people who challenged that claim to the spirit and they then show their true colors.
Physical harm, fear... while these things are there, these are not their main goal.
Their main goal towards humanity is deception... and that should comes as no surprise as Lucifer is describe as being the Father of Lies... should we expect his followers to act any less? Evil is not always going to be upfront... in fact most of the time it works in shadows and out of light.

God reveals to us in His Word that Satan can appear as an angel of light... doing good works and coming in peace. They are crafty and have had thousands of years to perfect their deceit.

They are extremely different

Daisy - what do YOU think about the subject?

I believe there is a fine line between ghost and demons. Ghosts are entities bound to this world. Whether they died an untimely death our simply have unfinished business. But we don't know why exactly hence the reason its called the paranormal

I believe there is a fine line between ghost and demons. Ghosts are entities bound to this world. Whether they died an untimely death our simply have unfinished business. But we don't know why exactly hence the reason its called the paranormal. Demons on the other hand were never human and exist for the mere purpose of their hatred for humans. They are a nuscence and are nasty entities to mess with. They'll separate the weakest from the family, the most vulnerable and make their life a living hell. Their smart and deceitful.they'll do anything for an easy target.they can portray themselves as children and prey on yours. They,aren't something I'd mess,with.

Sorry about the double post my phones acting up again.

Sammy is right... these are many of the ways a demon will use to gain a foothold in the family. They will especially work to separate family members from one another. They can do this by giving no manifestation at all to a father, while the mother or daughter may have constant experiences that put them through a living hell.

Personally, I see no good arguments for the existence of human spirits working in the earth after death.