Purim falls in February or March, on the Jewish calendar date of Adar 14, and begins as do all Jewish holidays at sunset the night before. Although Purim is not a major Jewish holiday in a religious sense, it is one of the most popular, especially for families with young children.

A common joke among Jewish people is that most Jewish holidays can be summarized using only three phrases: "They tried to kill us. We won. Let's eat." Purim fits this pattern well, as it celebrates the triumph of the Jews in ancient Persia over the evil Haman, who got King Ahasuerus to sign a decree calling for the hanging of all the Jews in the town of Shushan. The Jews were saved when the king's new queen, Esther, revealed that she was Jewish and sought his help in saving her people. Haman was hanged on the very gallows he had ordered constructed for hanging the Jews, and Esther's cousin Mordechai replaced Haman as the king's minister.

One of the most central Purim traditions is the reading, from beginning to end, of the Book of Esther, known also as Megillat Esther, or colloquially as "the whole Megillah." Synagogues hold Megillah readings on Purim eve and during the day on Purim. Attendees use noisemakers called graggers to drown out Haman's name, and children often dress in costume, usually as one of the characters in the Purim story. Many little girls look forward to dressing as Queen Esther, while boys seem split in their choices of bad guy Haman, hero Mordechai, or King Ahasuerus. Children may put on a skit about the Purim story or sing songs about the holiday such as "Wicked Wicked Man".

Even adults often masquerade on Purim, and some traditions hold that during this holiday, adults should drink enough alcohol that they can no longer distinguish between Mordechai and Haman in the reading of the Megillah.

Many synagogues and Jewish organizations hold Purim carnivals for children. These events typically include costume parades and contests and games for prizes. Decades ago the highlight of such carnivals was the chance for kids to win a goldfish as a premium prize at one of the game booths. Nowadays these Purim celebrations may feature more modern entertainment such as bouncy houses.

Purim traditions also include rituals that focus on providing for others and promoting friendship. Matanot la'evyonim is the practice of giving charity to those less fortunate, in the form of either food or money. When giving directly to people in need isn't possible, Jews can contribute through their synagogue. Throughout the holiday, gratitude and commemoration are incorporated into the daily prayers, with special sections focused on offering thanks for the miracles that have saved the Jews throughout history.

Shalach manos or mishloach manot is the act of giving gifts of food. People typically put together plates or baskets of food to give to two or more friends and family members. These gifts often include hamantashen, a traditional Purim pastry shaped like Haman's three-cornered hat. The pastries are filled with poppy, prune, apricot, or other tasty fillings.

Continuing the focus on food, Jewish families partake in seudat Purim, the festive meal. This meal often wraps up the night and day of festivities as families attend a seudah at their synagogue or host their own celebration.