The festival lasts for three days straight. Muslims all around the world celebrate The end of the month of Ramadan as Eid ul Fitr. The sighting of the moon decides the existence of eid. 
What is Eid ul-Fitr? 
Eid ul-Fitr means "festival of breaking the fast".
it marks the end of the fasting month of Ramadan of the Islamic calendar. The Muslims gather for the prayer in the morning on this occasion and calls for a celebration. People visit friends and relatives on eid. This eid is called the meethi eid where people offer sevaiyan to eat and sweeten the month by celebrating the end of the fasting month.

When does Eid ul-Fitr begin? 

The start of the eid is marked by the sighting of the new moon. The night before the eid is called as the Chaand Raat where people shop and eat and get ready for eid. The day of Ramadan as well as eid different every year. The month of Shawwal starts with eid. 
How do people celebrate?
The celebration of eid starts by offering a namaz altogether and eating of a sweet dish prepared at home. These prayers take place in halls, mosques and large grounds as well. People meet each other and greet eid, Mubarak. Then they visit the graveyard to visit the dead and pray for them on eid. 
People wear good clothes and give eidi to small children and donate charity to the underprivileged. 

How do people dress for Eid?
Some would wear clothes from their culture including kurta or hijab, while others buy something new to wear on this festival.