Yes, it's the highest festival in the Islamic year.
Well, I think most Muslims certainly do rember them but if you are asking about what we are celebrating then it has to do with several things. Shaykh Munajjid said:
Muslims celebrate Eid Aladha by slaughtering a sheep. The slaughtering of sheep is done in following the footsteps of Prophet Abraham when he was ordered by Allah (God) to slaughter his first child, Ishmael. When he told his son about it, his son told him to carry on with the order of Allah, and that he will be obedient and patient. As Abraham was tempting to slaughter Ishmael, Allah gave them a big and fat sheep to slaughter instead. The sacrificing of a sheep has become a ritual for Muslims every year in remembrance of the obedience of Abraham and Ishmael, peace be upon them. Our celebration of this day and the slaughtering of the sheep are in compliance with the teachings of our Prophet Mohammad, praising and peace of Allah be upon him.
The Prophet sall Allahu 'aleyhi wa sallam said:
‘The Day of ‘Arafah, the Day of Sacrifice and the Days of al-Tashreeq [the three days following the Day of Sacrifice] are a festival for us Muslims, and they are days of eating and drinking.’” (Narrated by al-Tirmidhi, 704; classed as saheeh by al-Albaani in Saheeh al-Tirmidhi, 620).
So we believe that God chose these days for us as a festival, so we celebrate. So this whole period in this month is really special. The first ten days of this month are the best days of this world. On the 9th day it will be the day of 'Arafah insha'Allah when, among other things, the verse was revealed in which God says that Islam has been perfected. Then, the 10th day, it will be Eid and we will commemorate Abrahams willingness to obey God. And the three days after that are also days of joy. So it's more than just one day.
