Passover is a Torahic holiday, the first of the Three Pilgrimage Festivals. 

The name of the holiday is derived from the Exodus 12: 27: “it is the sacrifice of the Lord’s Passover, who passed over the houses of the children of Israel in Egypt, when he smote the Egyptians, and delivered our houses”. This refers to the fact that the Plague of the Firstborn, which enabled the Exodus, did not strike the Israelites. The first festival, which includes the Seder dinner the prior evening, marks the day the Israelites left Egypt, and the second marks the day the Red Sea was torn before the fleeing Israelites. Between the two major festivals are festive days in which it is customary not to go to work or engage in commerce, etc., unless when the employer does not allow a vacation, or when losses could be caused, on when work is essential, such as medical services. Particular restrictions apply to some practices such as haircuts and shaving, laundering, construction, writing, etc.  

The main commandments of Passover are the prohibition on consuming and owning leavened dough throughout the seven days of the holiday, and the half day before it. On the morning of the Seder, one must stop consuming leavened dough and the complete elimination of dough from one’s home must be completed an hour later.