The origins of the Genie go way back to the ancient civilizations of the middle east. The original name in ancient text is spelled 'Djinn', (pronounced Jin). These supernatural beings had the power to grant wishes to those foolish enough to sell their souls and believe that their wishes would be properly granted. The Koran speaks of these creatures as being real entities and not mythological at all. Some Islamic writings reference that Allah created the Jin, while others say that these beings pre-date mankind altogether. There is also debate about whether they were a force of good or evil. Despite this, however, the majority of text in the Koran describe the Jin as being angry spirit creatures, born of smokeless fire. Alongside the first man, Adam, who was created and brought forth from the earth, the Jin had free-will just as Adam did. Unlike Adam though, who was always trying to seek the good and righteous side of his nature, the Jin preferred to seek the darker side of theirs.
As intended by Allah, the Jin were to be guardians and servants of Adam, however, from the beginning, they wanted no part of this intended role, unlike the Christian account in which Lucifer, accepted this role, but later grew envious and misused his authority, thus becoming Satan. Upon refusal to take part in Allah's scheme of things, the Jin were barred from the Garden of Eden and transformed into hideous, deformed creatures, subjugated to roam in the lowliest of places on earth like, ruins, graveyards, trash heaps, caves and dungeons.
While the Djinn exist in the earth, they populate an alternate dimension, not often seen by the human world. They are, in the very meaning of their name, 'hidden by sight'. Though the Jin exist on a different plane than that of man, they can watch and even influence humans into doing their bidding's. To guard against such beguiling influences, Allah provides a prayer of protection, but without strong religious faith these prayers are almost useless.
Some of the more powerful Jin can enter our world by transforming themselves into animal or human form. Playing the role of wizard, magician, sorcerer, or even someone known to us, such as a family member or friend. Again, the text is split on their reason for doing this. In some cases it is to bring ruin to mankind, but in other text their goal is a good and helpful one. You could say comparatively, that the Djinn are like the angels and demons of the Muslim faith. However, unlike the angels and demons of the Christian bible, who exist separately, the angels in God's service in heaven and demons in the service of Satan, who live in the belly of the earth, the Jin, as a whole, all live on the same plane of existence.