Muslims pray to celebrate Eid al-Adha in Naples, in southern Italy, last year
CNN  — 

In most of the Muslim world today, the faithful are celebrating Eid al-Adha, the second of two major holidays in Islam.

The day begins with morning prayers. The celebrations continue with visits to friends and family, exchange of gifts and feasts. Those who can afford it also slaughter an animal, like a cow or sheep, and share the meat with the less fortunate.

Here are five things to know about the holiday:

1. Pronounced EED al-UHD-huh, the holiday is also known as the Feast of Sacrifice. It is one of two Eid holidays observed by Muslims. The other is Eid al-Fitr, which follows the conclusion of Ramadan, the month of fasting.

Syrian children ride an attraction in the northwestern Syrian city of Idlib during Eid holidays last year.

2. Eid al-Adha commemorates when God appeared to Abraham – known as Ibrahim to Muslims – in a dream and asked him to sacrifice his son as an act of obedience. As Abraham was about to sacrifice his son, God stopped him and gave him a sheep to kill in place of his son. A version of the story also appears in the Torah and in the Bible’s Old Testament.

An Iraqi mother and her children prepare cookies for holiday in Basra, Iraq.

3. To commemorate God’s test of Ibrahim, many Muslim families sacrifice an animal and share the meat with the poor. They also are required to donate to charities that benefit the poor. Muslims also routinely exchange presents during the holiday.

A  vendor handles a goat at a livestock market in Hyderabad, India. Many Muslims sacrifice an animal to celebrate the holiday.

4. Considered one of Islam’s revered observances, the four-day religious holiday corresponds with the height of the Hajj, the pilgrimage to Mecca that all financially and physically able Muslims are required to undertake once in their lifetime. The pilgrimage annually draws 2 million Muslims.

A journey through Hajj, Islam’s special pilgrimage

Muslim pilgrims attend the evening prayers inside the Grand Mosque in Mecca

5. Because the festival depends on the sighting of the new moon, countries around the world sometimes celebrate it on different days.

Muslims pray in an open-air basketball field in the city of Corinth, near Athens, Greece, last year.

Eid Mubarak (pronounced EED muh-BAR-ack) and Eid Saeed are routine greetings used during the observance to offer best wishes.