Jinns are in Islamic Folklore. They are supposed to be demons. Jinns can be commonly described as genies, since both sound the same and are very alike. Unlike the Demons we know in things like Christianity, Jinns are the rulers of the underworld. And Satan is their leader.
The Jinns were made by Allah to worship him. Like men and angels. They had qualities such as intellect, discrimination, freedom and power.
The Jinn became Satan when it was told to kneel before Allah. And the Jinn refused. Angels and Allah himself told this Jinn to kneel before him but it refused. Allah then banished Satan to the underworld. Jinns then went to the underworld. And it has been told that he placed his throne on the sea.
Names for jinns. Jinn is normally referred to as an Amir (a resident Jinn) which means they live with people. There is also shaytan which is a Jinn that has turned wicked. There are three types of Jinns. The first one can fly through the air. The second one appears as snakes and dogs. And the third one appears as humans. The powers of Jinns are like shape shifters. They can take the form of almost anything including humans. That means all living creatures could be a Jinn. Yes Jinns can hurt humans if they are inclined to. They can possess bodies or just appear like someone and drive the person crazy enough to commit suicide. Can Jinns marry and produce offspring? Yes Jinns can marry and have offspring. Do Jinns eat? Yes they do. But they would use the opposite that humans and angels would use. Where do Jinns live? They live in places of impurity, such as deserts and ruins.
Later Muhammad smashed all the Jinn statues since he thought it was disrespectful towards god. Because people should not worship something that reminds someone of something. That's why there are NO paintings of Allah and Muhammad's face is whited out with paint. That's why Muslims are really good with designs, since they can't make pictures of religious people.
Today there have been “sightings of Jinns”. Personally I think they are fake. But if you really want to see some of the videos for yourself.