What is the Catholic Passover?

Passover is the eight-day festival that is celebrated in early spring, from the 15th through the 22nd of the Hebrew month of Nissan. It commemorates the Israelites being freed from Egypt. God helped free them by inflicting ten plagues on the Egyptians. God told the Jews to mark their doors with lamb's blood and He would then pass over these homes, hence the term "Passover". On Passover, Jewish families get together and have a dinner called "seder" (pronounced sayder). It involves prayers and the telling of the story of the exodus from Egypt, and Jews are not allowed to eat anything leavened, for example, breads (we eat Matzo instead).