What is meant by the branches of Islam and the matters of ijtihad concerning which the madhahib differed, and is it possible to mention all these branches and matters of disagreement and ijtihad concerning which they differed?

The branches of Islam and matters of ijtihad (independent reasoning) are rulings that are open to consideration, and in which differences of opinion are permissible. This is because they do not pertain to the fundamental principles of the religion or its general rules, nor is there a definitive, undeniable proof that would condemn anyone who differs. This divergence does not only occur among Islamic madhhabs (schools of thought), but even among the laws of the prophets, who differed only in the branches, due to their agreement on the fundamental principle of Tawhid (monotheism) and beliefs.