The following is one chapter of Islam 101:
The five pillars of Islam constitute the most basic tenets of the religion. They are:
1. Faith (iman) in the oneness of Allah and the finality of the prophethood of Muhammad (indicated by the declaration [the Shahadah] that, "There is no God but Allah and Muhammad is the messenger of Allah").
2. Keeping of the five scheduled daily prayers (salah).
3. Almsgiving (zakat).
4. Fasting (sawm).
5. Pilgrimage (hajj) to Mecca for those who are able.
The five pillars in and of themselves do not tell us a lot about the faith or what a Muslim is supposed to believe or how he should act. The second through fifth pillars — prayer, almsgiving, fasting, pilgrimage — are aspects shared by many religions. The finality of the prophethood of Muhammad, however, is unique to Islam.
To understand Islam and what it means to be a Muslim, we must come to understand Muhammad as well as the revelations given through him by Allah, which make up the Quran.
See a Glossary Of Islamic Terms for definitions.
Islam 101 was written by Gregory M. Davis, author of Religion of Peace?: Islam's War Against the World, and the producer/director of Islam: What the West Needs to Know.