Purim is a Jewish holiday observed on March 21, 2019. It commemorates the deliverance of the Jewish people in the ancient Persian Empire from destruction in the wake of a plot by Haman. According to the Book of Esther, in the Hebrew Bible, Haman, royal vizier to King Ahasuerus (presumed to be Xerxes I of Persia), planned to kill all the Jews in the empire, but his plans were foiled by Mordecai and his adopted daughter Queen Esther. The day of deliverance became a day of feasting and rejoicing.
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. Today, only Jerusalem celebrates Purim on the 15th. It is celebrated by giving mutual gifts of food and drink, giving charity to the poor, a celebratory meal, and public recitation of the Scroll of Esther, additions to the prayers and the grace after meals. Other customs include drinking wine, wearing of masks and costumes, and public celebration.
Purim has more of a national than a religious character, and its status as a holiday is on a lesser level than those days ordained holy by the Torah. Accordingly, business transactions and even manual labor are allowed on Purim. The four main mitzvot (obligations) of the day during Purim celebration are: Listening to the public reading, usually in synagogue, of the Book of Esther in the evening and again in the following morning, sending food gifts to friends, giving charity to the poor and eating a festive meal. (With material from: Wikipedia)