Islam is Built Upon Five
On the authority of Abdullah ibn Umar ibn Al-Khattab (رضي الله عنه ) who said: I heard the Messenger of Allah (صلي الله عليه و سلم) say:
Islam has been built on five [pillars]: testifying that there is no god but Allah and that Muhammad is the Messenger of Allah, performing the prayers, paying the Zakah, making the pilgrimage to the House, and fasting in Ramadan
[Bukhari and Muslim]