Lets get to the basics, a pillar is a structure that is used to support structures, such as buildings, homes, and other structures. So a pillar of Islam is used as a symbol in the sense that Islam the religion is supported by pillars. There are five of these pillars in the religion of Islam, these are Shahada (testimony), Salah (prayer), Zakat (charity), Sawm (fasting), and lastly Hajj (pilgrimage to Mecca). These five pillars are the core beliefs that Muslims follow, and in turn these pillars are considered the fundamental duties of a Muslim.
Shahada or Testimony, is the first pillar which means declaration of faith. All Muslims must declare their faith once they are mature enough. They do this by saying "a ilaha illa Allah wa-Muhammad rasul Allah" (There is no god but God and Muhammad is the prophet of God). By declaring this recitation, the person is not only accepting Allah as God, but also Muhammad as the last prophet.
Salah or prayer, is pretty straight forward. Praying is one of the main aspects of being a muslim. Muslims pray five times a day, during different times of the day. These timings are at dawn you pray (fajr), midday (zuhr), afternoon ('asr), sunset (maghrib) and evening ('isha). These prayers are supposed to be done whilst facing the Kabaah, which is situated North-East. Finding out the direction can be easily done with a real compass or compass app that can be downloaded as an app.
Although Zakat means charity, its direct translation is "to purify". Muslims are encouraged to give charity as often as they can, but the compulsory charity that any Muslim must give is 2.5% of their surplus wealth. Surplus wealth is often open for interpretation. The main idea behind zakat is that the wealth that an individual has, should be spread out, and to some degree divided among poor. This is so there isn't a huge divide, such as one living extravagantly, while others live in severe poverty.
During the holy month of Ramadan, Muslims have to fast every day from sunrise to sunset. This isn't limited to just food either, Muslims are expected to keep away from anything that distracts them from worshiping God during this month, as this is considered the most holy month. There are several things that Muslims achieve through fasting, some of them being, to some degree we too can relate to the poor who are starving, fasting is great for your health, and self-control is developed, as well as the heightened sense of spirituality which in turn makes them stay away from sins such as lying, lust, and back-biting.
Hajj (pilgrimage to Mecca)
The last pillar of Islam is Hajj, which basically means to go to Mecca, and conduct a series of rituals. Mecca is important to Muslims for many various reasons, but the main one being that it was the site for Muhammad's first revelation of the holy Quran, as well as being his birth place; additionally it is home to the kaaba, which is regarded the center of the IslÄmic universe. Hajj is compulsory on every Muslim that is physically and financially fit, as a result it is advised to make this pilgrimage when Muslims are in their prime age.