Passover or Pesach, is an eight day Jewish holiday of Biblical origin marking the birth of the Jews as a people and their emergence as a unique nation in history, devoted to God's will. It celebrates the liberation of the children of Israel from slavery in Egypt over 3000 years ago, under the leadership of Moses.
Passover is determined by the Jewish lunar calendar and begins on the eve of the fifteenth day of the month of Nisan. The English date varies from year to year, falling in March or in April.
It is prohibited by Torah law to own chametz (leaven) on Pesach. Therefore in the strict Jewish household they search and destroy chametz before Pesach. In most homes the process of cleaning begins weeks before Pesach. The house is scoured from top to bottom to remove all traces of chametz.
Chametz is basically defined as any grain product of any kind (including grain alcohol) that is fermented or capable of being fermented at any point in time. Bread products utilizing yeast to make them rise are the most common.
Instead of traditional products made from grains (anything that is Chametz, such as normal bread), Matzoh is required eating on Seder (a ritual banquet which reenacts the Exodus, conducted on both the first and second evenings of Passover), but optional during the remainder of this eight day holiday (although Matzoh is still the only grain type of product allowed to be eaten or kept in the household during the entire length of the holiday).
Matzah is a crisp, flat, unleavened bread, made of flour and water, which must be baked before the dough has had time to rise. It is the only type of "bread" which Jews may eat during Passover, and it must be made specifically for Passover use, under rabbinical supervision.
Eating Matzah on Passover commemorates the unleavened bread eaten by the Jews when they left Egypt in such haste that there was no time for the dough to rise.
This year on Wednsday evening April 16th (Erev Pesach -- the eve of Passover 5763) the eating of all Chametz ceases. On this day prior to the start of Passover the house is purged of all Chametz which is burned or sold. Once Passover begins the first candle is lighted (first night Yom Tov).
Only cooking utensils and eating vessels that have never had Chametz touch them can be used for the Seder diner which starts on the first night of Passover.
Its major feature is the reading of the Haggadah, which relates, in detail, the events of the Exodus of the Jewish people from ancient Egypt, complete with symbolic reenactments using Kosher wine, specially prepared Matzah, and bitter herbs.
The specially prepared Shmurah Matzah is made specifically for use at the Seder, with specially supervised flour according to particularly stringent Jewish traditions and laws. The bitter herbs (Maror) consisting of either romaine lettuce or horseradish, commemorate the harsh conditions of slavery in ancient Egypt.
Four cups of wine are consumed during the course of the Seder to commemorate the redemption of the Jewish people, the sanctity of the holiday and events related in the Haggadah. The Seder is a traditional occasion for Jewish families to gather together to reinforce their ties to Judaism.