:sl:
I'll let someone else answer in more detail, but for now read this :) .
What are the jinn?
The Jinn are a world of their own, different from that of humans or the angels. They do however, possess some characteristics in common with humans such as the ability to think and reflect. Similarly they have the ability to choose between the path of good and the path of evil in the same manner as humans. They, though differ from humans in other characteristics including one very important characteristic: Their origin.
They are called Jinn because they are obscured from human sight,
"Lo! He sees you he and his tribe, from whence you see him not" (al-araaf 27)
Their Origin
Allah has informed us that the Jinn have been created from fire as He says in the Quran,
"And the jinn did we create aforetime of essential fire" (al-Hijr 27) In surah al-Rahman (verse 15), He says,
"And the Jinn He did create of a smokeless flame of fire" According to Ibn Abbaas, Ikrimah, Mujaahid, Al-Hasan and others the meaning of marajin-min-nar, is "the extremity of the flame", and in one narration it is described as the purest and best (of fire). An-Nawawi said in his commentary to Sahih Muslim, "The smokeless flame of fire is that mixed with the blackness of fire."
In a hadith recorded by Muslim on the authority of Aisha, the Prophet (peace be upon him) said,
"The angels were created from light, the jinn were created from a smokeless flame of fire and Adam was created from what has been described to you [by Allah in the quran]"
When were they created
There is no doubt that the Jinn were created before mankind, as Allah says,
"Verily we created man of potter's clay of dark mud altered. And the Jinn did we create aforetime of a flameless fire" (al-Hijr 26-27). This verse clearly states that the Jinn were created before mankind. Some of the earlier scholars were of the opinion that they were created a thousand years before mankind, but for that statement they have no proof in the Quran or the Sunnah.
The names for the Jinn in the Arabic language
Ibn Abdul Barr said, "The jinn, according to the scholars of the language, are of different types:
1. If one is mentioning the jinn purely of themselves, they are called Jinni.
2. If one is mentioning the jinn that live among mankind, they are called aamar whose plural is amaar.
3. If one is mentioning the ones that antagonise the young, they are called arwaah.
4. If one is mentioning the evil ones that antagonise humans they are called Shaitan for the singular [and Shayateen for plural]
5. If they cause even more harm and become strong, they are called afreet.
Types of Jinn
The prophet (peace be upon him) said,
"There are three types of jinn: one that flies through the air, one that are snakes and dogs, and one which stay in places and travel about."