I decided to make this post in light of a question in another thread, and the replies therein.
The plural of Djinn is Djinn, the Singular is Djinni. Second, Genie and Djinn are not separate entities, they are the Anglicized and Romanized forms, respectively of the Arabic word Jinn or al-jinn (jinni singular), which loosely translates to spirit or demon, derived from the word jann, which means "to hide".
As for the nature of Jinn, this is a topic for debate. Though I will say the depiction of Jinn as demons is a relatively recent thing, via Islamic beliefs.
There are generally believed to be various classes of jinn, those being:
- Ghouls- Shapeshifting graveyard dwellers, typically nocturnal, malicious beings. Sometimes associated with alleged "shadow people". Of limited intellect, though the females are of slightly higher intellect than the males, they only use it to deceive and lure.
- Hinn- I could only find one source on this in my studies, in a book titled "Miraculous Aspects of Things Existing". These are essentially the animals of the Jinn.
- Ifrit- The typical depiction of the jinn, especially in Islamic lore. Beings of smokeless fire, intelligent, arrogant, not particularly fond of humans. Shaytan, the Islamic antagonist, also known as Iblis, falls under this category.
- Marid- The stereotypical wind vortex genie depicted in media. Proud, fond of flattery, not inherently hostile nor benevolent towards humans. The type of jinn that Solomon compelled to build his temple. Most famously the Jinni in the lamp, and the fisherman and the Jinni from the Arabic Folklore book 1001 Nights. Capable of shapeshifting. Bahamut, a figure from Arabic myth falls into this category.
- Nansas- Briefly mentioned in "1001 Nights" and more thoroughly in "Miraculous Aspects of Things Existing", these are, simply put, half-human half-animal.
- Palis- Again, only found reference of this sort of Jinn in "Miraculous Aspects of Things Existing", these are essentially just vampires, whom drink blood from the feet, hence the translation of their name from Arabic "Foot Licker".
- Shiqq- Yet another that is only mentioned in "Miraculous Aspects of Things Existing". Unintelligent, half beings. Hideous in appearance.
- Si'lat- The most impressive of the shapeshifters. Generally depicted as centaurs, they may assume any shape. Not particularly hostile, but sometimes attributed with mirages of water seen in deserts.
I do not personally view Jinn as a spiritual entity, so much as an astral one. It is my own belief, formed via my own workings, that they are of another plane of existence, living their lives as we live ours. Unlike other spiritual beings, they cannot be seen directly with the third-eye. Usually they may only be initially contacted through a series of long rituals, and only viewed through trance or indirectly through the third-eye with a mirror, with special markings upon its surface. Though, there is still the possibility that they are still spiritual in nature, with an exceptional nature, my work with them and my research leads me to believe otherwise. As with anything, it is open for interpretation, and no one individual's findings should be held as absolute truth.