Allah creates various jannah layers due to the levels people achieved in the world. According to the tafsir (commentary) and hadith scholars, jannah has one hundred levels.
“Verily, Paradise has one hundred levels and between each level is a distance like the distance between the earth and the sky.” [Al-Bukhari in as-Sahih, Kitab al-Jihad, Bab Darajat al-Mujahidin fi Sabilillah, Fath al-Bari, 6/11]
But the narrations about the number of the levels differ.
Ibn-i Abbas’s point of view is “Jannah has seven levels”
In a narration from Ibn-i Abbas (may Allah be pleased with him), it is stated that jannah has seven levels which are “Firdaws, Jannat al- Adn, Jannat-an Naim, Dar-ul Khlud, Jannat-ul Mawa, Dar-us Salam and Illiyyun. In each of the levels, there are degrees and grades which Mumins will have in return for their good deeds and righteousness. (Baydawi)
There are no other narrations about jannah’s being seven levels except this.
According to some scholars Jannah is eight levels
Some scholars express that jannah is eight levels which are described in the ayahs and hadiths as following:
1. Jannat al- Adn:
“Adn” means “recidence” and “eternal place”.
“(If you do so) He will forgive you your sins, and admit you into Gardens under which rivers flow, and pleasant dwelling in Gardens of 'Adn ['Adn (Edn) Paradise], that is indeed the great success.” (Surah as-Saf 12)
“Allah promiseth to the believers, men and women, Gardens underneath which rivers flow, wherein they will abide - blessed dwellings in Gardens of Eden. And - greater (far)! - acceptance from Allah. That is the supreme triumph.” (Surah at-Tawbah 72)
Our Blessed Prophet Muhammad (pbuh) stated that:”While the dwellers of Adn Jannah see their Lord, there is just the “Curtain of Glorious” between them and Allah (swt).“ (Bukhari)
"Allah (swt) created Jannat al- Adn, planted its trees meticulously. Then told her (the Jannah) to speak. And she said: “Mumins attended their desires.” (Hakim)
“Adn (Eden) Paradise (Gardens of Eternity) which they will enter, under which rivers flow, they will have therein all that they wish. Thus Allah rewards the pious.” (Surah Al Nahl, 31)
2. Jannat al- Firdaws
“Firdaws” means “garden which has all kinds of plants”. It is also described as the garden therein the grape vines.
“When you ask Allah (pbuh) for jannah, ask for Firdaws.” (Thirmidhi)
Because the Jannat al- Firdaws is over all jannahs and is superior to them, it is advised to be asked primarily. (Kutub-i Sitta)
3. Jannat an-Naeem:
“Naim” means a prosperous and peaceful life, living in wealth, welfare and blessings.
“ Lo! those who believe and do good works, their Lord guideth them by their faith. Rivers will flow beneath them in the Gardens of Delight. (Jannat-an Naim)” (Surah al Yunus, 9)
“And make me one of the inheritors of the Paradise of Delight (Jannat an-Naim).” (Surah as- Shuara, 85)
4. Jannat al- Mawa
“Mawa” means “place to take refuge; dwelling, home.” This level is also mentioned as the abode for the martyred (shahid) and the Mumins.
“But as for those who believe and do righteous deeds, for them are the Gardens of Retreat (Jannat al-Mawa)- a welcome (in reward) for what they used to do.” (Surah as- Sajdah, 19)
“And verily he saw him yet another descent (the night of Mi’raj- the Ascent) By the lote-tree of the utmost boundary. Nigh unto which is the Garden of Abode. (Jannat-ul Mawa)” (Surah an Najm 13, 14, 15)
5. Dar-ul Khuld:
Khuld means being eternal, everlasting; eternity, immortality.
“Say: Is that (doom) better or the Garden of Immortality (Dar-ul Khuld) which is promised unto those who ward off (evil)? It will be their reward and journey's end.” (Surah al- Furqan, 15)
6. Dar-ul Maqaam:
Means “the essence place to stay, land to dwell eternally, the safe place.”
“Who, of His grace, hath installed us in the mansion of eternity, where toil toucheth us not nor can weariness affect us.” (Surah al -Fatir, 35)
7. Dar-us Salaam:
Means home of peace and safety; abode of well-being.
“Allah calls (you) to the home of peace (to Jannah) and guides whom He wills to a Straight Path.”(Surah al-Yunus)
“For them will be the home of peace (Paradise) with their Lord. And He will be their Protector because of what they used to do.” (Surah al An`am, 127)
The highest level of Jannah…
Abode of the perfect Mumins…
The name of the lounge of the hafaza (protection) angels to where the deeds of the righteous are ascended. It is the closest level to the highest degree, the gate of consent in the hereafter.
There are one hundred levels in jannah
“Paradise is 100 levels; between each level and the next is the distance of 100 years and the Firdaws is the highest of them in degree, and from it the four rivers (of Paradise) emerge. And the throne is above it. So when you ask Allah, ask Him for al-Firdaws.” (Thirmidhi)
“Paradise is 100 levels; between each level and the next is the distance of 100 years (walking distance).” (Thirmidhi)
“Paradise is 100 levels. If all the worlds congregate in one of them, it surrounds in all." (Thirmidhi)
Some scholars indicated that the expression of “100 levels” refers to the “grades” that exist in each level of paradise.
Some scholars stated that expression of “100 levels” refers to the plurality. Jannah isn’t one level. It is 100 levels and the distance of each level is further than the other. The dwellers will dwell in the level appropriate to their deeds. (Kutub-i Sitta)
Hadrat Abdulqadir’i Gaylani wrote about this issue in his book” Gunyatut Talibin” as the following: “Jannah is 100 levels. In this world, just three of these 100 levels are explained through instance. The instances of that level are “gold, silver and light.” It is very hard for brain to comprehend the other levels."
Jannah has 8 doors
Abu Huraira (may Allah be pleased with him) narrated that our Prophet (pbuh) said:
“Whoever gives two units of sadaqah (charity) from his goods, he will be granted entry through all doors of jannah. Jannah has 8 doors. Those Muslims who are punctual in observing their Salah will be granted entry through “Bab us-Salaah” (The Door of Pray). Muslims who constantly observe the fast will be granted entry through “Bab ur-Rayyan” (The door of fast) Those Muslims who frequently give Sadaqah will be admitted into Jannah through Bab us-Sadaqah (the Door of Charity). Muslims who participate in Jihad will be granted entry through Bab ul-Jihad (the Door of jihad)” (Mukaashafat-ul Kulub)
In the “Interpretation of Abu-s Suud”:
“The reason why there eight doors of Jannah may be so: it is thought that these doors are related to the obliged organs. As is known, man’s obliged organs are eight: Heart, tongue, ear, eye, hand, foot, mouth, genitalia. Seven of these are open, one is secret which is heart. If the heart door-which faces Allah (swt) directly- is open, each of these eight organs -living upon the commands of Allah (swt)- may be an entrance door to jannah. By this way, one enters into the jannah through eight doors.
But, if the door of heart is closed and the soul declines, each of the seven outer organs becomes entrance doors to hell. It is the reason, why the jannah doors are eight while the doors of hell are seven. Allah (swt) knows the best." (Elmalili Hamdi Yazir)