Islam is a religion that many people in Iran follow. People in Iran believe that there is only one God, and they call him Allah. They also believe that the Prophet Muhammad is a messenger of Allah, and they try to follow his teachings.
There are two main types of Islam, Sunni and Shia. In Iran, Shia Islam is the dominant form of the religion. Shia Muslims believe that the Prophet Muhammad's cousin and son-in-law, Ali, was his rightful successor, and they follow the imams, who they believe are the descendants of Ali.
Iran has a long history with Islam. It was converted to Islam in the 7th century, and over the centuries, many influential Shia scholars and leaders have come from Iran. Today, Iran is an Islamic republic, which means that its laws and government are based on Islamic principles. The Supreme Leader, who is the highest religious and political authority in Iran, is also a Shia Muslim.
People in Iran practice Islam in different ways. Some are very religious and pray five times a day, fast during Ramadan, and do other religious rituals. Others are more secular and don't practice the religion as much. However, Islam still plays an important role in Iranian culture and society.