Imamate is the term used to refer to the leadership of the Islamic community after the death of the Prophet Muhammad. Imagine that you are playing a game with your friends and the friend who is leading the game suddenly has to leave. Now, you need to find a new leader to continue playing the game. This is similar to what happened after the death of Prophet Muhammad in the Islamic community. The question of who would lead the Islamic community after his death was a big one.
Some people believed that the new leader should be someone in the Prophet's family, while others believed that the new leader should be elected by the community. Those who believed that the new leader should be from the Prophet's family are called Shia Muslims, and they believe that leadership should be passed down through the Prophet's family. Those who believed that the new leader should be elected by the community are called Sunni Muslims, and they believe that the community should choose its own leader.
Shia Muslims believe in the concept of imamate, which means that the leader of their community is divinely appointed by God and has the authority to interpret Islamic law and guide the community in religious matters. You can think of it like a teacher who is chosen by the principal to lead the class and help the students learn.
In summary, imamate is the idea that the leader of the Muslim community should be chosen by divine appointment and have the authority to guide the community in religious matters. This concept is important to Shia Muslims, who believe that the leader should come from the Prophet's family, while Sunni Muslims believe that the community should choose its own leader.