Adhan is called out by a muezzin from the mosque five times a day, traditionally from the minaret, summoning Muslims for mandatory (fard) worship (salat). A second call, known as iqama, (set up) then summons Muslims to line up for the beginning of the prayers. The main purpose behind the multiple loud pronouncements of adhan in every mosque is to make available to everyone an easily intelligible summary of Islamic belief. It is intended to bring to the mind of every believer and non-believer the substance of Islamic beliefs, or its spiritual ideology. In modern times, loudspeakers have been installed on minarets for this purpose.
The adhan recites the Takbir (God is great) followed by the Shahada (There is no god but Allah, Muhammad is the messenger of Allah). This statement of faith, called the Kalimah, is the first of the Five Pillars of Islam.