"Imam" literally refers to anyone or anything holding a leading (moqaddam) and modeling (moqta’da) role. Exploration of the concept and instances of the word "imam" in the Quran suggests that the Quran includes this comprehensive literal meaning of the word with all its applications and the difference lies only with the type and level of modeling (moqta’daee). Also, a review and criticism of the views of the Shiite and Sunnite interpreters verifies that, contrary to the views of Fkhr-Razy, Alusi and many a Sunni commentators believe that "the highest human ranks of Imamate and Prophethood are identical", "the position of Imamate is definitely different from and superior to that of Prophethood and Messengership, and the highest human ranks of Imamate and Prophethood have some common and some distinct aspects. And finally, on the basis of what is discussed and introduced in this article, five ranks of Imamate are discernible from the Quran: 1) guarded tablet (loh-e mahfuz), 2) the revealed books, particularly the Quran, 3) the total Imamate which is superior to Prophethood and Messengership, 4) the Imamate of Prophethood and Messengership, and 5) the Imamate of the leading men in righteousness which comprises several ranks by itself.