The literal meaning of the word `Islam' is `to yield and submit.’
The prophet (PBH) explained it is the name of the five basic pillars in Islam:
(I) The first fundamental of Islam is to say `Ash'hadu Alla ilaha illallah-Va Ash ahadu Anna Muhammadu Rasoolullah' (there is no god but Allah and Muhammad is the messenger of Allah) vocally and making the meaning firm in the heart and to believe in this absolutely with all his heart.
"On the earth or in the sky, there is no one but Allah worthy of worship. The real being to be worshiped is Allah alone. Every kind of superiority exists in within him. No defect exists in him. His name is Allah." And Muhammad bin Abdullah is the servant and messenger of Allah. He was born in holy Makkah in the year 571 Monday April 21st and died July 12th 632 in holy Madeena.
(II) The second fundamental of Islam is to perform the ritual prayer five times a day at the prescribed times in accordance with all its conditions and compulsions. To perform it before its times by adapting wrong calendars prepared by ignoramuse’s people is a grave sin and such a prayer is not accepted. The ritual prayer has to be performed before the prescribed time is over, paying attention to its compulsions, conditions, and sunnats. In Islam ritual prayer is called `salah'. And salah is certain action and recitations, between takbeeratul ihram (the recitation of Allah Akbar with which salah begins) and `salam' with which the salah ends turning head into both right and left sides respectively.
(III) The third fundamental of Islam is to give `Zakat' of one's wealth. In Islam, Zakat means to give a certain percentage of one's property (its prescribed scale or amount called nisab) to eight kinds of people named in Qur'an. There are four kinds of zakats: Zakat of gold and silver, the Zakat of commercial goods, the Zakat of stock animals (sheep, goat and cattle) and the Zakat of all kinds of substances necessity produced from earth. The first three are given at the completion of a year and the fourth is given immediately after the harvest.
(IV) The fourth fundamental of Islam is to take fast every day of the month of Ramadan, one of the months of 'Hijrah' calendar. In Islamic sense fast (sawm) is abstention from three things during the day times: eating, drinking and sexual interaction or intercourse. The months begin upon seeing the new moon in the sky. It must not begin by the means of calculation or prediction.
(V) The fifth fundamental of Islam is to perform Hajj if possible once in the life. One, who is healthy and safe and has enough money to go and come back from the city of Makah, after the sufficient property for the subsistence of his family during the time of his absence, has to perform Hajj and Umrah.
This is the sequence of fundamentals of Islam (five pillars of Islam). Most of the scholars gave prominence to this sequence. Also please visit us for morals in Islam.