What are the two main branches of Islam?

Answer: Sunni and Shia Islam

Explanation: The division of Sunni and Shia Muslims dates back to the beginning, namely after Muhammad's death. According to Sunni Islam, who are the majority in the Muslim world, the successor to Muhammad, that is Caliph can be someone who is qualified enough and credible to be a religious leader. On the other hand, Shia Islam advocates the thesis that the successor to Muhammad must be his cousin, at the place of Caliph, i. e. religious leader.

Sunni Islam

Shia Islam.