The Quran is the primary source of law in the Islamic Legal System. It is considered to be the direct word of God, and it contains a number of legal injunctions that are binding on all Muslims.

The Sunnah is the secondary source of law in the Islamic Legal System. It consists of the sayings, actions, and tacit approvals of the Prophet Muhammad. The Sunnah is considered to be a reliable source of law because it is believed to be a reflection of the Prophet's understanding of the Quran.

The Ijma is the third source of law in the Islamic Legal System. It is the consensus of the Muslim community on a particular legal issue. The Ijma is considered to be a reliable source of law because it is believed to reflect the collective wisdom of the Muslim community.

The Qiyas is the fourth source of law in the Islamic Legal System. It is the process of analogical reasoning, whereby a new legal issue is decided by reference to a similar issue that has already been decided. The Qiyas is considered to be a reliable source of law because it is based on the principle of justice and equity.

The two main schools of thought in the Islamic Legal System are the Sunni and the Shia. The Sunni are the majority sect of Islam, and they believe that the Prophet Muhammad appointed Abu Bakr as his successor. The Shia believe that the Prophet Muhammad appointed Ali ibn Abi Talib as his successor.

The four main schools of law in the Sunni tradition are the Hanafi, the Maliki, the Shafi'i, and the Hanbali. These schools are named after their founders, Abu Hanifa, Malik ibn Anas, al-Shafi'i, and Ahmad ibn Hanbal.

The three main schools of law in the Shia tradition are the Ja'fari, the Zaydi, and the Isma'ili. These schools are named after their founders, Ja'far al-Sadiq, Zayd ibn Ali, and Isma'il ibn Jafar.

The main source of law in the Ja'fari school of law is the Hadith. The Hadith are the sayings, actions, and tacit approvals of the Prophet Muhammad and his Ahl al-Bayt (family).

The main source of law in the Zaydi school of law is the Quran. The Zaydi believe that the Quran is the only source of law that is binding on all Muslims.

The main source of law in the Isma'ili school of law is the Ta'wil. The Ta'wil is the allegorical interpretation of the Quran and the Sunnah.

The main difference between the Sunni and Shia schools of law is that the Sunni believe that the Prophet Muhammad appointed Abu Bakr as his successor, while the Shia believe that he appointed Ali ibn Abi Talib.

The main difference between the Hanafi, Maliki, Shafi'i, and Hanbali schools of law is that they differ in their interpretation of the Quran and the Sunnah.

The main difference between the Ja'fari, Zaydi, and Isma'ili schools of law is that they differ in their interpretation of the Quran and the Sunnah.

The state is responsible for enforcing the law, interpreting the law, and making the law.

Religion and politics are intertwined in the Islamic Legal System. The Quran and the Sunnah provide guidance on a wide range of political issues, such as the role of the state, the rights and responsibilities of citizens, and the conduct of war.