Eid-Al-Fitr is an Islamic festival marking the end of Ramadan (also knoawn as Ramzan), the month of fasting. Muslims all over the world fast daily in the month of Ramadan from dawn to dusk known as Roza. After sunset, they break the Roza and consume food. This is done for the entire month of Ramadan till the day of Eid. People generally wish each other ‘Eid Mubarak’, ‘Eid-Ul-Fitr Mubarak’, ‘Happy Eid’ and so on depending on each language. For more information on Eid, click this link – http://en.wikipedia.org/wiki/Eid_al-Fitr
Although Eid is an Islamic festival, it is celebrated by people of all faiths world over.