Passover, the Jewish festival in celebration of the Jews' freedom from slavery and the flight from Egypt, begins this year at sunset on April 18.
Although traditions vary throughout the world, the basics are as follows: The holiday lasts seven or eight days (depending on where it's being celebrated), and the first night of Passover begins with a ceremonial dinner, called a Seder, where the story of the Exodus is told.
The food and wine customs of a given Seder are elaborate, and differ between regions and families, but some factors remain constant.