Definition: Imam is an Arabic word that refers to the spiritual leader, or the one who stands above all else as the spiritual and sometimes the political leader of the Muslim community, or ummah. An imam is also the one who leads congregations in Friday prayer at the mosque. As such imams may be compared with the clergy in the Christian church, though Muslims are likely to bristle at the comparison.
Shiite Islam emerged out of the tradition of the "Twelve Imams," considered the legitimate and infallible spiritual descendants of the Prophet Muhammad. Imams' decisions in Shiite Islam are binding and allegedly infallible, much like those of popes in the Catholic church.
More recently, Shiites have given the title of imam to their spiritual and political leaders, especially in Iran, where Ayatollah Ruhollah Khomeini, founding his own creatively opportune tradition, consolidated the notion of the spiritual and political guardian of the state under the all-encompassing banner of "supreme leader."
In Sunni Islam, imams are like eminent judges, some of whom, like Abu Hanifah, founded leading juridical schools.
