Purim is the Jewish festival of redemption! The celebration of the failure of Haman's plot to annihilate the Jewish people. This year Purim will be celebrated on March 24th & 25th.
According to the Book of Esther, Haman, the royal vizier to the Persian King Ahasuerus, planned to kill all the Jews in the empire, but his plans were foiled by Mordechai and his adopted daughter, Queen Esther.
The heroes of the story are Esther, a beautiful young Jewish woman living in Persia, and her uncle Mordechai, who raised her as if she were his daughter. Esther was taken into the house of Ahasuerus, King of Persia. Esther found favor with King Ahasuerus' and he loved Esther more than his other women and made Esther his queen, but the king did not know that Esther was a Jew, because Mordechai told her not to reveal her identity.
The villain of the story is Haman, an arrogant, egotistical advisor to the king. Haman hated Mordechai because he refused to bow down to Haman, so Haman plotted to destroy the Jewish people. Haman told the king, "There is a certain people scattered among the peoples in all the provinces of your realm. Their laws are different from those of every other people's, and they do not observe the king's laws; therefore it is not befitting the king to tolerate them." Esther 3:8. The king gave the fate of the Jewish people to Haman, to do as he pleased with them. Haman planned to exterminate all of the Jews.
Mordechai persuaded Esther to speak to the king on behalf of the Jewish people. This was a dangerous thing for Esther to do, because anyone who came into the king's presence without being summoned could be put to death. Esther fasted for three days to prepare herself, then went to see the king, unsummopned!! He welcomed her. Later, she told him of Haman's plot against her people. The Jewish people were saved, and Haman and his ten sons were hanged on the gallows that had been prepared for Mordechai.
This day of deliverance became a day of feasting and rejoicing. Purim is celebrated by giving mutual gifts of food and drink (mishloach manot), giving charity to the poor (mattanot la-evyonim), and a celebratory meal (se'udat Purim). The scroll of Esther is read publicly (kriat ha-megillah). During the reading of the scroll of Esther at the mention of the name "Haman" a deafening noise erupts - noise makers, rattles and feet stomping are employed to drown out the name of evil. An additional blessing (al hannisim) is added to prayers and grace after meals on this day. Other customs include drinking wine, wearing of masks and costumes, and public celebration.