What is understood from Quranic verses and the ahadith is that, similar to heaven, hell has different levels, and sinners will be put into these levels depending on the number and type of their sins.
In a hadith from Imam Baqir about the verse: “لَها سَبْعَةُ أَبْوابٍ لِكُلِّ بابٍ مِنْهُمْ جُزْءٌ مَقْسُوم” “It has seven gates, and to each gate belongs a separate portion of them.” the Imam says: “I have been informed that God has made seven levels for hell.”
The first level which is the highest is called “Jahim”. People at this level stand on hard rocks and their brains boil from the heat.
The second level is called “Ladhaa”. At this level, the heat peels off the skin of the feet, hands and head. The fire calls to itself the people who opposed God’s commands and gathered wealth.
The third level is called “Saqar”. In it is a fire that does not leave anything and nothing is immune from it. It completely changes the form of the skin. Nineteen angels are in charge of this level.
The fourth is “Hutamah” and from it rise flares the size of palaces. They rise so fast, as if they are yellow camels that disperse in every direction. Whoever is touched by them turns black, like kohl.
The fifth is “Haawiyah” (falling to the Asfal al-Safilin, i.e., the lowest of the low) in which groups of people call out: “O Owner [the name of an angel there]! Help us.” When the angel comes to them, he brings yellow and red dishes to them in which is a bad-smelling water. When they drink the water their skin becomes like heated metal. Once they pick up the dish to drink from it, the flesh on their face falls into it due to its heat. This is what the following verse refers to: “وَ إِنْ يَسْتَغيثُوا يُغاثُوا بِماءٍ كَالْمُهْلِ يَشْوِي الْوُجُوهَ بِئْسَ الشَّرابُ وَ ساءَتْ مُرْتَفَقاً”  “If they cry out for help, they will be helped with a water like molten copper which will scald the faces. What an evil drink, and how ill a resting place!” Whoever goes to that level of hell will be in fire for seventy years, and every time his skin burns, new skin will replace it.
The sixth is called “Sa’ir” in which there are three hundred tents of fire, and every tent has three hundred palaces of fire and every palace has three hundred houses of fire and every house consists of three hundred types of pain and torture caused by fire. This is what God is referring to when He says: “إِنَّا أَعْتَدْنا لِلْكافِرينَ سَلاسِلَ وَ أَغْلالاً وَ سَعيراً” “Indeed We have prepared for the faithless chains, iron collars, and a blaze.)”
The seventh and last level is called “Jahannam” in which is “Falaq”. Falaq is a ditch in hell that when opened, fire blazes out. This level consists of the most painful of punishments….
 See: The Seven Heavens, Question 1859 (site: 1915).
 The reason for this name is that “Hawiyah” is derived from the root word “هوی”, which means to fall. The name refers to falling into Asfal al-Safelin.
 The name of the angel guards of Hell.
 Majlisi, Muhammad Baqir, Bihaar al-Anwaar, vol. 8, pp. 289-290, al-Wafaa’ Institute, Beirut, 1409 AH.