Purim (Hebrew: פורים Pûrîm "lots") is a Jewish holiday that commemorates the deliverance of the JewishPersian Empire from Haman's plot to annihilate them, as recorded in the BiblicalBook of Esther (Megillat Esther). According to the story, Haman cast lots to determine the day upon which to exterminate the Jews. people of the ancient
Purim is celebrated annually according to the Hebrew calendar on the 14th day of the Hebrew month of Adar, the day following the victory of the Jews over their enemies; as with all Jewish holidays, Purim begins at sundown on the previous secular day.
Purim is characterized by public recitation of the Book of Esther (keriat ha-megilla), giving mutual gifts of food and drink (mishloach manot), giving charity to the poor (mattanot la-evyonim), and a celebratory meal (se'udat Purim);
other customs include drinking wine, wearing of masks and costumes, and public celebration.(*text from wikipedia*)