The Prophet S.A.W said "Islam is built upon five pillars: the Testimony that there is no god except Allah and that Muhammad is the Messenger of Allah, establishing the Prayer, paying Zakat, making the Hajj to the House and Fasting in Ramadan' (Al-Bukhari and Muslim).
This short treatise succinctly presents each of these five pillars with the detail necessary for their correct understanding and application.