What are the five pillars of Islam?

The testimony of faith, the five daily prayers, zakat, fasting in Ramadan, and pilgrimage to Makkah for those able.

The five pillars of Islam are the testimony of faith (shahadah), the five daily prayers (salah), the obligatory charity (zakat), fasting the month of Ramadan (sawm), and pilgrimage to Makkah (hajj) once in a lifetime for those able to make it. Together they are the minimum framework of a Muslim's practice.

The list comes from the Prophet himself. Ibn 'Umar reported that he said: "Islam is based on five: to testify that none has the right to be worshipped but Allah and that Muhammad is Allah's Messenger, to establish the prayer, to pay zakat, to perform hajj, and to fast in Ramadan" (Sahih al-Bukhari 8).

1. Shahadah. Bearing witness that there is no god but Allah and that Muhammad is His Messenger. It is the doorway into Islam and the belief the other four rest on.
2. Salah. Five prayers at set times each day and night. "Establish prayer, give zakah, and bow down with those who bow down" (Quran 2:43).
3. Zakat. An annual payment, usually 2.5%, on savings above a minimum threshold, given to the categories of people the Quran names (Quran 9:60).
4. Sawm. Fasting from dawn to sunset through Ramadan: "fasting has been prescribed for you as it was prescribed for those before you, so that you may become mindful" (Quran 2:183).
5. Hajj. Pilgrimage to the Ka'bah, obligatory once on "whoever is able to find a way to it" (Quran 3:97).

The pillars are not the whole of Islam. They sit alongside the articles of faith (belief in Allah, His angels, books, messengers, the Last Day and divine decree) and the moral teaching that runs through the Quran and Sunnah. But they are what every Muslim is required to practise, which is why they are taught first.