Two Major Branches
Sunni and Shi'i are the two largest branches of Islam, with the overwhelming majority of Iranians practicing Shi'i Islam. About 90 percent of Iranians practice Shi'ism, the official religion of Iran. By contrast, most Arab states in the Middle East are predominantly Sunni. Islam is a universalizing religion that tries to spread the ideas of Allah (God). Islam is a very influential religion on surrounding countries.