Hajj is a pilgrimage to the holy city of Mecca in Saudi Arabia, and it's one of the Five Pillars of Islam. Here's a simple explanation of the Hajj pillar:

Hajj is a journey that Muslims make to the city of Mecca at least once in their lifetime if they are physically and financially able. It takes place during the Islamic month of Dhu al-Hijjah, specifically from the 8th to the 12th of the month. Hajj is a time when Muslims from all around the world come together to fulfil this sacred obligation.

During Hajj, Muslims perform a series of rituals that commemorate the actions of the Prophet Ibrahim (Abraham) and his family. These rituals include:

1. Tawaf: Pilgrims circle the Kaaba, a cube-shaped structure in the centre of the Masjid al-Haram (the Grand Mosque in Mecca), seven times in a counterclockwise direction.

2. Sa'i: Pilgrims walk back and forth between the hills of Safa and Marwa, following in the footsteps of Hajar (Hagar), the wife of Prophet Ibrahim, who searched for water for her son Isma'il (Ishmael).

3. Wuquf: Pilgrims spend a day of standing in prayer and supplication at the plain of Arafat, where Prophet Muhammad delivered his farewell sermon.

4. Stoning of the Devil: Pilgrims throw stones at three pillars representing Satan, symbolising the rejection of temptation and evil.

5. Animal Sacrifice: Pilgrims sacrifice an animal, usually a sheep, goat, or cow, in commemoration of Ibrahim's willingness to sacrifice his son Isma'il as an act of obedience to Allah.

Completing these rituals fulfils the requirements of Hajj, and pilgrims return home with a sense of spiritual fulfilment and renewal. Hajj is a time of unity, humility, and devotion, as Muslims from diverse backgrounds come together to worship Allah and seek His mercy and forgiveness.

Hajj holds great significance in Islam, as it serves as a physical and spiritual journey of purification and renewal. It's a reminder of the unity of the Muslim ummah (community) and the importance of submitting to the will of Allah. Through the experience of Hajj, Muslims strengthen their faith, deepen their connection to Allah, and reaffirm their commitment to living a righteous and obedient life.