Final answer:
Shi'a or Shia Islam refers to the minority branch of Islam that believes in the leadership of Muhammad's genuine successors through Ali. They also believe in the divine authority of certain members of Muhammad's family called imams.
Step-by-step explanation:
The minority branch of Islam that holds Muhammad's genuine successors descended from his son-in-law, Ali is called Shi'a or Shia Islam. Shi'a Muslims believe that leadership of the Muslim community should reside in the family of Muhammad through Ali and his wife Fatima. They also believe in the divine knowledge, charisma, and authority of certain members of Muhammad's family, whom they refer to as imams.
Learn more about Shi'a Islam