Islam is based on 5 fundamental pillars:
1) Shahadah: is a statement professing monotheism and accepting Muhammad as God’s final messenger. The shahadah is a set statement normally recited in Arabic: ašhadu an la ilaha illállah wa ashhadu ‘anna Muhammadan rasulu lLah “I profess that there is no god but Allah (Arabic word for God) and Muhammad is the messenger of God.
2) Salah: Salah is the daily prayer for Muslims. Salah consists of five prayers: Fajr, Dhuhr, Asr, Maghrib, and Isha’a. Fajr is said at dawn, Duhr is a noon prayer, Asr is said in the afternoon, Maghrib is the sunset prayer, and Isha is the evening prayer. Each prayer consists of a certain amount of rakat or units. A prayer either consists of two, three, or four rakat. All of these prayers are recited while facing Mecca.
3) Zakat or alms-giving is the practice of charitable giving by Muslims based on accumulated wealth, and is obligatory for all who are able to do so. It is considered to be a personal responsibility for Muslims to ease economic hardship for others and eliminate inequality. Zakat consists of spending 2.5% of one’s wealth for the benefit of the poor or needy, including slaves, debtors and travellers. A Muslim may also donate more as an act of voluntary charity (sadaqah), rather than to achieve additional divine reward.
4) Saum or fasting fasting is an obligatory act during the month of Ramadan. Muslims must abstain from food, drink, and sexual intercourse from dawn to dusk during this month, and are to be especially mindful of other sins.
The fast is meant to allow Muslims to seek nearness to God, to express their gratitude to and dependence on him, atone for their past sins, and to remind them of the needy.
Fasting during Ramadan is obligatory, but is forbidden for several groups for whom it would be very dangerous and excessively problematic. These include pre-pubescent children, those with a medical condition such as diabetes, elderly people, and pregnant or breastfeeding women. Observing fasts is not permitted for menstruating women. Other individuals for whom it is considered acceptable not to fast are those who are ill or traveling. Missing fasts usually must be made up for soon afterward, although the exact requirements vary according to circumstance.
5) Hajj or pilgrimage occurs during the Islamic month of Dhu al-Hijjah to the holy city of Mecca, and derives from an ancient Arab practice. Every able-bodied Muslim is obliged to make the pilgrimage to Mecca at least once in their lifetime if he or she can afford it. When the pilgrim is around 10 km (6.2 mi) from Mecca, he must dress in Ihram clothing, which consists of two white sheets. Both men and women are required to make the pilgrimage to Mecca. After a Muslim makes the trip to Mecca, he/she is known as a hajj/hajja (one who made the pilgrimage to Mecca). The main rituals of the Hajj include walking seven times around the Kaaba, touching the Black Stone, travelling seven times between Mount Safa and Mount Marwah, and symbolically stoning the Devil in Mina.
The full article can be found at: http://en.wikipedia.org/wiki/Five_Pillars_of_Islam