What the whole thing stands on
Five, and only one of them is done every day.
بُنِيَ الإِسْلاَمُ عَلَى خَمْسٍ شَهَادَةِ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَنَّ مُحَمَّدًا رَسُولُ اللَّهِ، وَإِقَامِ الصَّلاَةِ، وَإِيتَاءِ الزَّكَاةِ، وَالْحَجِّ، وَصَوْمِ رَمَضَانَ
Buniya-l-islāmu ʿalā khams: shahādati an lā ilāha illā-Llāhu wa anna Muḥammadan rasūlu-Llāh, wa iqāmi-ṣ-ṣalāh, wa ītāʾi-z-zakāh, wa-l-ḥajj, wa ṣawmi Ramaḍān
Islam is built on five: testifying that there is no god but Allah and that Muhammad is the Messenger of Allah, establishing the prayer, giving the zakat, the pilgrimage, and fasting Ramadan.
Where this comes from
Built on, not made of. They are what the rest stands on rather than the whole of it.
The full narration
Narrated Ibn 'Umar: Allah's Messenger (ﷺ) said: Islam is based on (the following) five (principles): 1. To testify that none has the right to be worshipped but Allah and Muhammad is Allah's Messenger (ﷺ). 2. To offer the (compulsory congregational) prayers dutifully and perfectly. 3. To pay Zakat (i.e. obligatory charity) . 4. To perform Hajj. (i.e. Pilgrimage to Mecca) 5. To observe fast during the month of Ramadan
Source
Ṣaḥīḥ al-Bukhārī · 8
- Agreed upon as authentic (al-Bukhārī / Muslim)