Matzo, unleavened bread

Unleavened bread, i.e. bread with no yeast, is a type of bread prepared with grain flour and water, like all other bread, but without the fermentation process.
Unleavened bread is used as a ritual food during Passover in memory of the hasty exodus from Egypt, during which, according to the Bible and oral tradition, the Jews had no time to let their bread rise before baking.