As part of the Islam religion, all true Muslims must perform 5 duties, called the Five Pillars of Faith. These are given here in their original order:
Shahada (affirmation) The duty to recite the creed: "There is nothing worthy of worship save Allah, and Muhammad is the Messenger of God"
Salat (prayer) The duty to worship the One God in prayer five times each day
Zakat (almsgiving) The duty to give away alms and to help the needy
Siyam (fasting) The duty to keep the Fast of Ramadan
Hajj (pilgrimage) The duty to make the pilgrimage to Mecca at least once in a lifetime
i got this from http://www.theholidayspot.com/ramadan/five_pillars.htm