Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to pray four rakahs behind the imam at Mina, and when he prayed by himself he would pray two rakas.
Prayer is one of the five pillars of Islam and it is very important for Muslims all over the world. It helps us stay connected with Allah and remember Him throughout our day-to-day lives no matter where we are or what we are doing. Prayer can be done individually or in congregation with an imam leading them, but either way it should be taken seriously as a form of worshiping Allah Almighty.