Passover, or Pesach, is an eight day observance which begins at sunset on the 15th day of Nisan in the Hebrew calendar. During this time, Jews celebrate the flight of the Israelites from Egyptian slavery in the 1200's B. C. E.
A ceremonial feast known as the Seder takes place on the first two nights of Passover. Symbolic foods, including unleavened bread, are placed on the table.
The word Passover is derived from the tenth plague God placed on Egypt for keeping the Israelites in slavery. According to the Bible, God killed the first born child in Egyptian homes but "passed over" the Israelites' homes which were marked with the blood of lambs.