Eid al-Fitr and Eid al-Adha are the two annual festivals of Islam. Eid al-Fitr marks the end of Ramadan, and Eid al-Adha comes at the end of Hajj and remembers Prophet Abraham's willingness to sacrifice his son for God.
The fuller answer
On both Eids, Muslims wear their best clothes, pray a special congregational prayer in the morning, give charity, visit family and friends, and share food. Eid al-Fitr starts with a charity (zakat al-Fitr) given to the poor so that everyone can join the celebration.
On Eid al-Adha, Muslims who can afford it sacrifice a sheep, goat, cow or camel, and divide the meat into three parts: for the family, for relatives and friends and for the poor. It recalls how God replaced Abraham's son with a ram once Abraham showed his obedience.
And when he reached with him [the age of] exertion, he said, "O my son, indeed I have seen in a dream that I [must] sacrifice you, so see what you think." He said, "O my father, do as you are commanded. You will find me, if Allah wills, of the steadfast."
This answer follows the mainstream Sunni understanding and is general learning, not a fatwa. Where Muslims differ, the answer says so. Have a question of your own? Write to us.