Muslims across the UK will celebrate Eid al-Fitr tomorrow to mark the end of Ramadan.
It's a day of celebrations and for children it often means lots of presents! The name is often shortened to 'Eid'.
You might have also heard of a festival called Eid al-Adha, which is also referred to as 'Eid'.
Read on to find out more about both of these festivals and the differences between them.
The word 'Eid' means 'feast' or 'festival'.
Each year Muslims celebrate both Eid al-Fitr and Eid al-Adha, but the names often get shortened to just 'Eid' and that's why it can be confusing.
Eid al-Fitr - which means 'festival of the breaking of the fast - is celebrated at the end of Ramadan, which is a month when many adult Muslims fast.
Eid al-Adha - which means 'feast of the sacrifice' - is celebrated just over two months later, at the same time when many Muslims perform the Hajj pilgrimage.
Festivals in Islam are based on the lunar calendar, which is around 11 days shorter than the solar calendar - the calendar which most people in the world use in their day-to-day life.
Being based on the lunar calendar means the dates of both Eids change each year, but Eid al-Fitr is always a little over two months before Eid al-Adha.
On both Eids, many Muslims will go to special Eid prayers at their local mosque and have a day of celebrations with family and friends.